Tougher Sanctions
Some lawmakers said they would seek remedies against Russia in Congress.
Several senators from both parties backed tougher sanctions on Russia. McConnell and House Speaker Paul Ryan, who called Russia's government "menacing," said their chambers could consider additional sanctions on Russia.
Congress overwhelmingly passed a sanctions law last year targeting Moscow for election meddling. In April, the U.S. Treasury imposed sanctions on Russian officials and oligarchs in one of Washington's most aggressive moves to punish Moscow.
Even before the allegations of Russian meddling, tensions were high over Moscow's concerns about NATO expansion, Russian annexation of the Crimea peninsula from Ukraine in 2014 and its military backing of Syrian President Bashar al-Assad in the Syrian civil war.
Some U.S. lawmakers have suggested passing resolutions voicing support for intelligence agencies, or spending more to enhance election security and prevent cyber attacks.
Republican Senator Bob Corker, chairman of the Senate Foreign Relations Committee, said congressional leaders were searching for the most effective response.
"We’re trying to figure out what would be an appropriate way to push back," Corker told reporters. "You know the president can do more damage in 15 minutes at a press conference than we can undo in six months of passing resolutions."
Corker said "the first step" would be hearing from U.S. Secretary of State Mike Pompeo, who will testify next Wednesday before the Senate Foreign Relations Committee.
Senate Democrats said they wanted the American interpreter at the Helsinki meeting to testify to Congress on what was said during the private Trump-Putin session.
U.S. intelligence agencies concluded last year that the Russian government interfered in the 2016 election campaign and sought to tilt the vote in Trump's favor, which Moscow has denied. Special Counsel Robert Mueller is investigating that allegation and any possible collusion by Trump's campaign.
Trump has denied collusion and casts Mueller's probe as a witch hunt that aims to detract from his election victory.
Not all Republicans were angry with Trump's conduct in Helsinki. "The president did a good thing by meeting with Putin," Senator Rand Paul told CBS' "This Morning" program, comments that won him public thanks from Trump on Twitter.
Russia's political and media establishment heralded the summit as a victory for Putin in breaking down Western resolve to treat Russia as a pariah.
"The West's attempts to isolate Russia failed," read the headline in state-run newspaper Rossiisskaya Gazeta.
