U.S. President Donald Trump and Secretary of State Mike Pompeo are meeting Tuesday in Washington with Russian Foreign Minister Sergei Lavrov, with the two nuclear powers discussing the possibility of extending their last remaining major arms control deal.

The officials, meeting as Democrats unveiled impeachment charges against Trump, also plan to talk about election security and national security, White House spokesman Hogan Gidley told the Fox Business Network.

"It's incumbent on any American president to try and build relationships across the world," Gidley said.

It is Lavrov's first visit to Washington since May 2017, when Trump was first enmeshed in allegations that he cooperated with Russia to help him win the 2016 election and was accused of sharing classified information with the Russian diplomat at their White House meeting. U.S. special counsel Robert Mueller concluded after a lengthy investigation that Russia meddled in the election to help Trump win, but that there insufficient evidence to prove Trump's campaign conspired with Moscow.

Russia has denied any interference in the election three years ago, a claim Lavrov renewed after meeting with Pompeo, before talks later in the day with Trump.

"All speculations about our alleged interference in domestic processes in the United States are baseless," Lavrov said. "There are no facts that would support that."

Pompeo said, "I made clear, (any Russian election interference) was unacceptable."

Trump is facing impeachment allegations centering on his efforts to get Ukraine to investigate one of his chief 2020 Democratic political rivals, former Vice President Joe Biden, and a debunked theory that Kyiv worked to undermine Trump's 2016 campaign, with Trump's request coming at a time when he was withholding $391 million in military aid Kyiv wanted to help fight pro-Russian separatists in eastern Ukraine.

Pompeo said he told Lavrov that the U.S. considers the Crimean peninsula, which Moscow unilaterally annexed from Ukraine in 2014, to still be part of Ukraine.

Lavrov, speaking through an interpreter, said, "We talked about strategic stability, arms control. We spoke frankly and business-like. It is useful to talk to each other, however difficult this period in our relationship is."

The top U.S. diplomat said the impeachment allegations would not impinge on the talks with Lavrov.

"We didn't pick this date to coincide with the process on Capitol Hill, but we can't allow the zaniness that's taking place on Capitol Hill to impact our job," Pompeo told conservative broadcaster One America News on Monday.

New START treaty

Russian President Vladimir Putin has called for the quick renewal of the New START arms control treaty that does not expire until February 2021. It was negotiated under Trump's predecessor, former President Barack Obama, obligating the two powers to halve their arsenals of strategic nuclear missile launchers.

The Trump administration has not ruled out a treaty extension, but wants a new pact to include China. Beijing has increased its arsenal, but it is much smaller than that held by Washington and Moscow.

Earlier this year, the U.S. withdrew from the Cold War-era Intermediate Range Nuclear Forces treaty, which curbed the number of missiles that could hit European cities, contending that Russia was violating the agreement.

Other topics

Pompeo, Trump and Lavrov are also expected to discuss Ukraine, Iran, North Korea and Syria. Russia, which backs Syrian President Bashar al-Assad, has increased its role in the Syrian conflict after Trump withdrew most U.S. troops from Syria.

After Lavrov's White House visit 2 1/2 years ago, The Washington Post reported that Trump shared classified information with him and Sergey Kislyak, Russia's then-ambassador to Washington, about a threat from the Islamic State terrorist group.

The U.S. ally that provided the information did not authorize Trump to divulge it, but it led to restrictions on the use of laptops in the cabins of commercial flights from the Middle East, the newspaper said.

Trump later said he had the "absolute right" to share "facts pertaining to terrorism and airline flight safety."