Kremlin: Donald Trump invites Russian President Vladimir Putin to White House

WASHINGTON – President Trump has invited Vladimir Putin to the White House, but much planning remains amid renewed strains in the U.S.-Russian relationship, the Kremlin said Monday.

While “Trump proposed holding a meeting at the White House in Washington,” Putin foreign policy aide Yury Ushakov told reporters in Moscow that some issues need to be resolved.

Trump signed off on a U.S. plan to expel 60 Russian diplomats and intelligence operatives and to close a Russian Consulate in Seattle in retaliation for a poison attack on an ex-Russian spy and his daughter.

"Against the backdrop of these events, it's difficult to discuss the possibility of holding a summit," Ushakov said, though he added he hopes that "one day, at one time or another, we can arrive at the start of a serious and constructive dialogue."

The White House said Trump and Putin discussed a meeting during a recent phone call, with the White House being one of several options for a site.

“As the President himself confirmed on March 20, hours after his last call with President Putin, the two had discussed a bilateral meeting in the ‘not-too-distant future’ at a number of potential venues, including the White House," White House press secretary Sarah Sanders said. "We have nothing further to add at this time."

More: Trump congratulates Putin after Russian president's re-election victory

More: Trump: Putin denies Russia meddling in 2016 election

The United States and its allies have formally condemned Russia over the poisoning of former Russian spy Sergei Skripal and his daughter; Russia has denied the allegations and is planning to kick U.S. officials out of its country.

There's also an ongoing special counsel investigation in the United States into Russian interference in the 2016 presidential election, and into any links with Trump's campaign.

Trump has said in recent weeks he wants to meet with Putin to discuss pressing issues, including the campaign to pressure North Korea into giving up its nuclear weapons programs.

During their March 20 phone conversation, Trump congratulated Putin on his re-election, despite claims of rigged balloting.

Trump and Putin also spoke last year on the sidelines of international summits in Germany and Vietnam.