WASHINGTON (CNN) -- President-elect Donald Trump's nominee to be secretary of state broke with his future boss on key foreign policy issues at his confirmation hearing Wednesday, backing the Trans-Pacific Partnership, denouncing Russian aggression in Ukraine, and affirming his belief in climate change.
Former ExxonMobil CEO Rex Tillerson -- who came under fire from both Democrats and Republicans -- said he wasn't against TPP, a massive trade pact that Trump condemned as he made staunch opposition to free trade deals a centerpiece of his presidential campaign.
"I do not oppose" TPP, Tillerson told the Senate Foreign Affairs Committee. "I share some of (Trump's) views regarding whether the agreement that was negotiated serves all of America's interests the best."
Tillerson also blasted Russia's invasion of Ukraine as an "illegal action" -- something Trump hasn't done -- and said he even would have sent the country defensive weapons to use against Moscow.
In a striking exchange, Tillerson admitted that he'd only spoken to the President-elect about world affairs in general terms, and that they haven't discussed Russian policy, telling the Senate panel "that has not yet occurred."
Tillerson praised sanctions as a deterrent, although he cautioned that imposing them can hurt American businesses. "In diplomacy, it is useful to have a stick that is in your hand so that whether you use it or not, it becomes part of that conversation," Tillerson said.
And he took steps in his opening remarks to strike an overall tougher line on Moscow than Trump has to date, saying, "Russia must know that we will be accountable to our commitments and those of our allies, and that Russia must be held to account for its actions."
On climate change, Tillerson told the Senators he believes "the risk of climate change does exist and the consequences of it could be serious enough that actions should be taken." In contrast, Trump has in the past described climate change as a hoax perpetrated by China to hurt US manufacturers, although he recently acknowledged the possibility that human activity could be a contributing factor.
He expressed respect for Mexico, calling it "a longstanding neighbor and friend of this country." In sharp contrast to Trump, who said during the campaign that the country sends undocumented rapists and criminals to the US, Tillerson said, "I would never characterize an entire population by any single term at all."
And unlike Trump, who has repeatedly questioned the utility of NATO and its members' financial contributions to the alliance, Tillerson expressed clear support.
He was asked whether the US should ignore the clause that requires members to come to each others' defense unless other members paid more. "I would not recommend that, no sir," he said.
Tillerson encountered repeated challenges on Russia and ExxonMobil's track record on climate change and its opposition to sanctions against rogue regimes.
It was enough, at the hearing's halfway point, for Senate Democratic Leader Chuck Schumer of New York to tweet about the President-elect or "PEOTUS" and his State Department nominee.
"Tillerson hearing raises real questions as to whether PEOTUS & cabinet are prepared to stand up to Putin, Iran & represent US interests," Schumer said.
In a departure from the pattern, Tillerson noted his position on the nuclear deal with Iran was consistent with Trump's. He told senators that while "no one agrees with the ultimate objective" to stop Iran from getting a nuclear weapon, he feels there should be a "full review of that agreement as well as any number of side agreements that are part of that agreement."
And he echoed Trump's frequent condemnations of China, calling Beijing's attempts to control airspace and its territorial claims "illegal actions." He said that China's construction of artificial islands to further its territorial claims were "akin to Russia's taking of Crimea. It's taking of territory that others lay claim to."
He also wouldn't push back against Trump's predilection for making foreign policy statements on Twitter that could undermine him while he is traveling the world.
"I don't think I will be telling the boss how he ought to communicate with the American people, Tillerson said. "That's going to be his choice." But Tillerson added that he was confident that however Trump communicated, it would be "supportive of that policy we both agreed on."
Tillerson, who said he hadn't received any classified briefings on the alleged Russian hacks, agreed that it's a "fair assumption" that Russian President Vladimir Putin authorized the attacks.
For weeks, Trump has denied or played down Moscow's involvement in efforts to meddle in the US election, although Wednesday, at a press conference Wednesday, Trump said, "I think it was Russia."
At the hearing, Democrats -- and some Republicans -- came out swinging.
Democrats questioned why in his prepared opening remarks Tillerson didn't mention Russia's alleged hacking of US elections, and they hammered his views on human rights and ExxonMobil's ties to Russia.
Florida Republican Sen. Marco Rubio went after Tillerson about Russia's violations of human rights and its alleged war crimes in Syria, pointing to information in the public record about civilians being targeted in the Syrian city.
"Is Vladimir Putin a war criminal?" Rubio demanded.
"I would not use that term," Tillerson said. "Those are very, very serious charges to make, and I would want to have much more information before reaching a conclusion."
Rubio said he found Tillerson's answer "very discouraging" and later in the hearing pressed the nominee on human rights standards in China and Saudi Arabia. Tillerson hedged again, refusing to call China "one of the world's worst human rights violators" and saying that these are "centuries-long cultures."
Sen. Robert Menendez, a New Jersey Democrat, challenged Tillerson on whether his business experience prepares him to represent the US to the world. "Diplomacy is not the same as deal making," Menendez said.
He went on to question where Tillerson's and Trump's views actually align and asked if the two had discussed US policy toward Russia.
Tillerson said he and Trump had talked about world issues "in a broad construct and in terms of the principles that are going to guide that." But when Menendez said he assumed "Russia would be at the top of that, considering all of the actions that are taking place," Tillerson said, "That has not occurred yet, senator."
"That's pretty amazing," Menendez shot back.
Menendez also challenged Tillerson on ExxonMobil's lobbying activities in direct opposition to US policy.
He cited the company's membership in a group that lobbied against Iran sanctions and Exxon's pursuit of a deal in Iraqi Kurdistan despite US opposition. And he brought into the hearing room documents showing millions in dollars of Exxon spending against sanctions on Iran and Russia.
"What message are you now going to be able to send to American businesses who are intent on pursuing their own interests at the expense of US policies and potential political stability in foreign countries," the New Jersey senator asked.
"I have never lobbied against sanctions personally," Tillerson said. "To my knowledge, Exxon never directly lobbied against sanctions. Not to my knowledge."
"There was lobbying here," Menendez told him. "It's a little amazing that you don't know Exxon was lobbying on these issues."
Maryland Democratic Sen. Ben Cardin later put into the record documents showing Exxon had spent $3.4 million lobbying against the Iran Sanctions Act.
Tillerson also tangled with Virginia Democratic Sen. Tim Kaine over long-standing allegations that ExxonMobil misled the public and its investors about internal research that outlined the threat of climate change. The company's shareholders have filed a class action lawsuit against the company in Texas, and it faces a similar lawsuit in Massachusetts as well.
"Do you lack the knowledge to answer my question or are you refusing to answer my question?" Kaine challenged the nominee.
"A little of both," Tillerson said.
Cardin, the ranking Democrat on the committee, pointed to Trump's longstanding refusal to acknowledge the Intelligence Community's assessment about Russian hacking. "We need to stand up to that bully in Moscow," Cardin said.
Cardin and other Democrats quizzed Tillerson on ExxonMobil's business deals with Russia, indicating that they "supported directly or indirectly" some of Putin's more aggressive actions.
"It's not too great of a distance from Exxon business partnerships to Putin's slush funds" for disinformation and other activities, Cardin charged.
The former ExxonMobil CEO claims close ties to Putin, having overseen the company's partnership with a state-owned energy giant there, work that earned him the country's highest award for non-citizens.
In opening remarks that were interrupted by a shouting protestor, Tillerson tried to strike a balance, saying that "where cooperation with Russia based on common interests is possible, such as reducing the global threat of terrorism, we ought to explore these options."
"We need an open and frank dialogue with Russia regarding its ambitions, so that we know how to chart our own course," he said. "Russia must know that we will be accountable to our commitments and those of our allies, and that Russia must be held to account for its actions."
And he validated NATO allies' concerns about Russian aggression but said that some of the blame lies with the Obama administration.
The US "sent weak or mixed signals with 'red lines' that turned into green lights," Tillerson said. "We did not recognize that Russia does not think like we do."