The U.S. on Wednesday delayed Russian President Vladimir Putin's upcoming visit to Washington until 2019. 

President Donald Trump invited Putin to the U.S. this fall, but Trump's national security advisor said the meeting would be delayed due to the ongoing special counsel’s probe into Russia's alleged attempt to influence the 2016 presidential election and the Trump campaign's possible cooperation with that effort.

"The President believes that the next bilateral meeting with President Putin should take place after the Russia witch hunt is over, so we’ve agreed that it will be after the first of the year,” National Security Advisor John Bolton said in a statement. 

Trump and his administration have derided Special Counsel Robert Mueller's investigation as a "witch hunt."

The Kremlin has yet to officially accept the invitation, and has been coy about whether Putin will eventually do so. Top Kremlin aide Yuri Ushakov said Tuesday that there is a need for a second meeting between the leaders, but added "there are other options" Trump and Putin could pursue. 

The White House announced last week that Trump had directed Bolton to extend the invitation to Putin amid criticism of Trump's handling of a summit with close NATO allies and subsequent meeting with Putin in Helsinki, Finland.

The U.S. intelligence community determined in January 2017 that Russia sought to interfere in the election in a bid to undercut Democratic nominee Hillary Clinton.

Trump appeared to back Putin's denials of any role in the effort during their meeting before reneging on his comments after he returned to Washington.

Putin acknowledged at the summit that he favored the then-Republican nominee because Trump "was the one who wanted to normalize relations with Russia," but has consistently maintained the Kremlin had no part in interfering in the election.