WASHINGTON—Donald Trump’s secretary of state nominee painted a vision for a pragmatic, stronger U.S. foreign policy and faced extensive questions on Russia during testimony before the Senate Foreign Relations Committee today.

“We will never apologize for who we are or what we hold dear,” said Rex Tillerson, ExxonMobil’s CEO from 2006 to 2016. “We will see the world for what it is, be honest with ourselves and the American people, follow the facts where they lead us, and hold ourselves and others accountable.”

Tillerson criticized the Obama administration for not following through on its promises and not holding other countries to their commitments. He cited dangers from China and Russia but identified Islamic terrorism as the greatest threat to the United States.

“Defeating ISIS must be our foremost priority in the Middle East,” said Tillerson, who pledged also to win the war of ideas. “I will ensure the State Department does its part in supporting Muslims around the world who reject radical Islam in all its forms.”

Sens. John Cornyn and Ted Cruz, both Texas Republicans who are not on the committee, introduced Tillerson, 64, as a lifelong Texan whose 41-year career with ExxonMobil made him well-qualified to become the nation’s top diplomat. Former Secretary of State Robert Gates and former Sen. Sam Nunn, D-Ga., also spoke in support of his confirmation.

Tillerson said he would, if confirmed, fully divest himself of financial interest in ExxonMobil and for the first year would recuse himself from any matters involving his former company, in accordance with the law. He said after that he would consult with counsel, spurning Democratic calls to recuse himself for his entire tenure.

Lawmakers repeatedly drilled Tillerson about his views on Russia, where ExxonMobil has vast business interests, and Russian President Vladimir Putin, whom Tillerson knows personally. The most explosive exchange came from Sen. Marco Rubio, R-Fla., who asked a string of questions about Putin—including whether he was a war criminal.

“I would not use that term,” Tillerson said.

Rubio launched into a detailed account of Putin’s offenses, including attacks on civilians in Aleppo, Syria, the deaths of numerous political opponents, and wars in Chechnya, which some estimate killed as many as 300,000 people.

Tillerson noted his lack of access to classified information and said he would need all of it before making a judgment (reasoning he later used when asked if Saudi Arabia was a human rights abuser).

“There’s so much info out there about what’s happened in Aleppo,” Rubio shot back. “It should not be hard to say Vladimir Putin has committed war crimes in Aleppo.”

Committee chairman Sen. Bob Corker, R-Tenn., sensing the significance of the exchange, twice circled back for clarification. He asked Tillerson if he would acknowledge Putin’s actions as war crimes if he had sufficient information to prove they occurred. Tillerson said yes, but Democrats later pressed him more on the issue.

Rubio’s questioning signaled he’s not close to supporting Tillerson’s confirmation, which is crucial: Republicans hold a single-seat advantage on the committee, 11-10, so Rubio and 10 Democrats could block Tillerson. Sen. Rand Paul, R-Ky., also seemed skeptical.

Members of both parties pressed Tillerson on the role of sanctions, citing past statements in which he called them ineffective. Tillerson told lawmakers he never lobbied against sanctions and considers them “an important, powerful tool,” but “poorly designed sanctions can be worse than no sanctions at all if they convey a weak response.”

Tillerson said a perceived weak response to Russia’s illegal annexation of Crimea emboldened Putin, whose goal is to reassert his country’s importance on the global stage. Tillerson said his response would have included urging Ukraine to put all of its military assets on its border with Russia and announcing arms, intelligence, and air surveillance cooperation with Ukraine.

“What Russia would have understood was a powerful response that showed ‘this stops right here,’” said Tillerson, who vowed to live up to America’s NATO obligations, including use of force, if necessary.

On multiple occasions, Tillerson said aid is a key lever of foreign policy that he would use when possible.

“Our values are our interests when it comes to human rights and humanitarian assistance,” Tillerson said. “Our leadership demands action specifically focused on improving the conditions of people the world over, utilizing both aid and economic sanctions.”

Tillerson said he’s seen first-hand the positive effects of PEPFAR (President’s Emergency Plan for AIDS Relief) in Africa, a program started under President George W. Bush and continued under the Obama administration: “It’s probably brought more goodwill than any other program on the continent.”

In nine hours of testimony, no senator asked Tillerson about his tenure running the Boy Scouts or LGBT issues, which Secretary of State John Kerry called “the core of our commitment to advancing human rights” in 2015 when he unveiled the first-ever special envoy for LGBT rights. Critics say the Obama State Department has often prioritized LGBT rights at the expense of traditional human rights and lethal persecution against numerous people groups, including Yazidis, Christians, and Shiite Muslims.