President Trump’s top diplomat faced withering questions from lawmakers Wednesday about the president’s ability to steer American foreign policy and his lack of transparency, as the White House scrambled to present a tougher stance toward Russia.

Secretary of State Mike Pompeo’s appearance before the Senate Foreign Relations Committee came as the White House postponed a second summit with Russian President Vladi­mir Putin amid criticism of Trump’s conflicting statements on Russian interference in the 2016 presidential election.

In an effort to reassure lawmakers, Pompeo said the president accepts the views of the intelligence community that Russia interfered in the election, and he declared that the United States would never recognize Putin’s annexation of Crimea from Ukraine.

But Tennessee Sen. Bob Corker, the top Republican on the panel, told Pompeo that lawmakers are “filled with serious doubts about this White House and its conduct of American foreign policy.”

He challenged Pompeo to satisfy bipartisan concerns that the White House is “making it up as they go” and that Pompeo himself may not know what is happening.

“The administration tells us, ‘Don’t worry, be patient, there is a strategy here.’ But from where we sit, it appears that in a ‘ready, fire, aim’ fashion, the White House is waking up every morning and making it up as they go,” Corker said, complaining that senators have been unable to get straight answers to basic questions about what Trump may have said to Putin when the two leaders met in Helsinki last week.

Pompeo testily assured senators that Trump had relayed the contents of the meeting afterward.

Russia and concerns that Trump is too cozy with Putin dominated the three-hour session. The hearing was a symbolic step for Republicans who have frequently set aside long-held policy views about Russia, North Korea and other issues to suit Trump’s un­or­tho­dox approach.

In a sign that the White House wanted to blunt criticism from the president’s own party, the administration issued a declaration about its views on Crimea, including that Republican-approved sanctions will remain in place, hours before the questioning began. White House national security adviser John Bolton then issued a statement formally postponing the follow-up Putin summit until next year.

Corker, a frequent Trump foil who is not seeking reelection this year, said Trump appeared “submissive and deferential” in his interactions with Putin, adding that Trump is “antagonizing our friends and placating those who clearly wish us ill.”

Corker’s frustrations followed a week of walk-backs, reversals and clarifications from a Trump administration trying to account for the president’s freewheeling comments about Russia and the 2016 election.

In recent days, Senate Republicans have made public remarks opposing a future meeting between Trump and Putin, which had been previewed by White House press secretary Sarah Huckabee Sanders last week.

Democrats in Congress, meanwhile, unleashed a torrent of criticism, going so far as calling Trump’s news conference with Putin “treasonous” and placing a rare demand for the president’s interpreter to testify before Congress about what the two presidents discussed.

On Wednesday, Pompeo said critics were unfairly characterizing Trump administration policy toward Russia as soft, and he ticked off a list of aggressive steps taken, including the expulsion of 60 Russian spies and diplomats, the sanctioning of Russian oligarchs and the provision of lethal weapons to Ukraine.

When confronted with specific questions about the summit, Pompeo repeatedly recited U.S. policy, prompting senators to accuse him of withholding details about the discussions.

Sen. Jeanne Shaheen (D-N.H.) asked whether Trump talked to Putin about removing U.S. troops from Syria. Pompeo replied that “there’s been no change to U.S. policy.”

“That’s not exactly the question,” Shaheen said.

Sen. Robert Menendez (D-N.J.) repeatedly asked whether Trump and Putin discussed sanctions related to Crimea. Pompeo did not answer the question directly but said it was U.S. policy not to lift sanctions imposed after Russia annexed Crimea.

“Presidents are entitled to have private meetings; I’m telling you what U.S. policy is here,” Pompeo said.

“We don’t know the truth of what transpired in those two hours,” Menendez shot back.

In a later exchange, Pompeo accused Menendez, the panel’s top Democrat, of playing political games.

Menendez shouted at Pompeo, a former tea party Republican congressman.

“If President Obama had done what President Trump did in Helsinki, I’d be peeling you off the Capitol ceiling, so please don’t talk to me about politics,” Menendez said.

The tension over what transpired in the meeting has been exacerbated by the fact that the Russian government has shared more details about it than the U.S. side has.

Last week, Russian Col. Gen. Mikhail Mizintsev said Moscow had already sent formal proposals to Washington for joint efforts to fund the reconstruction of Syria and facilitate the return home of millions of Syrians who fled the war, following “agreements reached” by Trump and Putin.

The announcement surprised U.S. allies and lawmakers, as U.S. officials insisted that no agreements were made.

In the hearing, Pompeo acknowledged that Trump and Putin talked about finding a political resolution in Syria, dealing with displaced people and protecting Israeli security interests, but he insisted “there’s been no change in U.S. policy with respect to our activities in Syria.”

In Moscow, Russian officials have reacted with surprise to the bipartisan backlash to the Helsinki summit. Typically, the Kremlin would welcome a follow-up invitation from the United States for another presidential meeting, but Kremlin foreign policy adviser Yuri Ushakov said Tuesday that it might be better for the “dust to settle before having a businesslike discussion” between Trump and Putin given the current “atmosphere” in Washington.

The hearing also provided the first opportunity for lawmakers to ask Pompeo about Trump’s meeting with North Korean leader Kim Jong Un in Singapore last month. Sen. Edward J. Markey (D-Mass.) expressed concern that there is “no verifiable evidence that North Korea . . . is denuclearizing.”

“I am afraid at this point that the Trump administration is being taken for a ride,” he said.

“Fear not, senator,” Pompeo responded.

The top diplomat, in keeping with Trump’s public support of the negotiations, expressed confidence that the North Koreans understand the U.S. definition of denuclearization and have agreed to denuclearize.

Pompeo would not, however, detail whether the United States has obtained an inventory of North Korea’s stockpile or say whether Kim’s government continued to develop nuclear weapons for submarines or chemical and biological weapons. He acknowledged that Pyongyang is still producing fissile materials and that human rights abuses continue.

Carol Morello and Karen DeYoung contributed to this report.