US President Donald Trump Photo: IC

US President Donald Trump warned Moscow against meddling in next year's election, the White House said Tuesday, but Russia's foreign minister denied the issue came up in a Washington meeting that drew controversy for occurring at all.

On the very day that House Democrats unveiled impeachment charges against Trump related to election interference, Russian Foreign Minister Sergey Lavrov met Trump behind closed doors at the White House after saying he sought more cooperation. 

The White House in a statement said that Trump "warned against any Russian attempts to interfere in United States elections and urged Russia to resolve the conflict with Ukraine."

Speaking to reporters moments afterward, Lavrov said he had not seen the White House account but said, "We haven't even actually discussed elections."

US intelligence found that Russia manipulated social media to sway the 2016 election in Trump's favor.

The mogul-turned-president is fond of denouncing the "Russia hoax" and has pressed an alternative theory, roundly rejected by US intelligence, that rival Ukraine in fact interfered in the election.

Lavrov, holding a news conference earlier with Secretary of State Mike Pompeo, seized on the idea of a Ukrainian plot, saying it showed "the absurdity of the accusations against us."

Pompeo stood firm that "our Russian counterparts" interfered in 2016 and issued his own warning.

"The Trump administration will always work to protect the integrity of our elections, period," Pompeo said. "Should Russia or any foreign actor take steps to undermine our democratic processes, we will take action in response."

Trump is facing impeachment after the White House delayed nearly $400 million in aid to Ukraine, which is battling Russian-backed separatists, as he pressed Kiev to investigate the election theory and to dig up dirt on his domestic rival Joe Biden.

Democrats said that Lavrov's visit only confirmed suspicions about Trump, who according to protocol would rarely receive a foreign minister.

Trump also invited Lavrov to the White House during his last visit to the US capital in May 2017. After that meeting, The Washington Post reported that the US leader shared with Russia classified details on a plot involving the Islamic State extremist group.