The US Speaker of the House Paul Ryan appears to be setting up a showdown with Donald Trump on Russia.
The top Republican in the House of Representatives, Mr Ryan has previously been reluctant to criticise the US president.
But Mr Trump’s words at a news conference after his meeting with Russian president Vladimir Putin have angered many in US political circles, including some from his own party.
Mr Trump had blamed his own country’s “foolishness and stupidity” for the poor state of the relationship between the two countries.
He also appeared to accept the Russian president’s word over that of his own intelligence agencies regarding alleged Russian meddling in the 2016 US election.
Mr Trump had said that, despite having “great confidence” in his intelligence services, he thought Mr Putin had been “extremely strong and powerful in his denial”.
Mr Trump is just hours away from a meeting with members of Congress behind closed doors and Mr Ryan has hinted that it may not be an easy day for the president.
Mr Ryan said that the US “stands by NATO allies and all countries facing Russian aggression”, adding: “Let’s be very clear – Russia meddled in our election”.
The Speaker said he was willing to consider additional sanctions on Russia and that Congress would make sure they were not able to “get away with (election meddling) again”.
“Russia is a menacing government that does not share our interests and it does not share our values,” he said.
Mr Ryan is not the only powerful Republican to have criticised Mr Trump’s behaviour towards Russia – Senate Foreign Relations Chairman Bob Corker, and former House Speaker Newt Gingrich are among those who have joined in.
Mr Gingrich, the former House speaker, called the president’s comments “the most serious mistake of his presidency” while Mr Corker said the comments made the US “look like a pushover”.
Mr Trump turned to his favourite medium Twitter to blame the media coverage of the Helsinki meeting with the Russian leader, writing that the “fake news (has) gone crazy”.
Mr Trump added: “I had a great meeting with NATO.
“They have paid $33 Billion more and will pay hundreds of Billions of Dollars more in the future, only because of me. NATO was weak, but now it is strong again (bad for Russia).
“The media only says I was rude to leaders, never mentions the money!”
About 20 minutes later, he tweeted again: “While I had a great meeting with NATO, raising vast amounts of money, I had an even better meeting with Vladimir Putin of Russia.
“Sadly, it is not being reported that way – the Fake News is going Crazy!”
He then returned to his familiar Twitter refrain: “The economy of the United States is stronger than ever before!”