The bipartisan leadership of the Senate Intelligence Committee is requesting federal agencies preserve all records relevant to the committee's investigation into Russia’s impact on the 2016 presidential election, a Senate aide confirmed to NBC News.

Republican Sen. Richard Burr of North Carolina and Democratic Sen. Mark Warner of Virginia sent the letters Friday as questions continue to surface about whether members of then-candidate Donald Trump’s inner circle had contact with Moscow during the campaign. The letter itself and a list of recipients has not been released.

“That doesn't mean that there's anything there. It just means they need to do some things that satisfy their committee,” White House Chief of Staff Reince Priebus said on NBC News’ “Meet The Press” on Sunday.

“As long as they do their job, and we cooperate with them, they'll issue a report, and the report will say there's nothing there,” he added.

The letter was sent the same day FBI Director James Comey visited Capitol Hill to discuss Russia with lawmakers.

The Senate committee is currently working on a bipartisan investigation into Russia's interference in the 2016 election, an investigation that they have said will also include any interactions Trump staff had with Russian officials after the election. The New York Times reported Trump aides had constant contact with Russian officials throughout the campaign, a charge Priebus denied.

National Security Adviser Michael Flynn resigned last week after it was revealed he had misled Vice President Mike Pence and other top administration officials about conversations he had with the Russian ambassador to the United States after Trump’s victory.