Trump again says Russia controversy is 'all a big hoax'

President Trump capped a week of contradictory statements about Russian activities during the 2016 presidential campaign by tweeting, "it is all a big hoax" Sunday evening.

"So President Obama knew about Russia before the Election," Trump tweeted. "Why didn't he do something about it? Why didn't he tell our campaign? Because it is all a big hoax, that’s why, and he thought Crooked Hillary [Clinton] was going to win!!!"

It was not clear precisely what Trump considered a hoax -- the ongoing investigation into whether his campaign colluded with Russian officials, or the notion that Russia had interfered with the election campaign at any point. However, the tweet echoed comments he made in an interview with Fox News' Sean Hannity that aired Monday.

"He thought Hillary Clinton was going to win and he didn’t want to do anything to disturb it," Trump said of Obama at the time. "And frankly, when I won, he said, 'This is the biggest deal.' But before I won, he said, 'This is nothing and it can't happen.' It’s a very dishonest deal."

Following his now-infamous news conference with Russian President Vladimir Putin in Helsinki on Monday, Trump repeatedly attempted to reassure the American public that he accepted the intelligence community's unanimous conclusion that Kremlin interference had taken place.

On Tuesday, the president tried to claim that he'd used a "double negative" and meant to say "wouldn't" instead of "would" in a key sentence at his press conference about who was responsible for election meddling.

"The sentence should have been: I don't see any reason why I wouldn't -- or why it wouldn't be Russia," the president said Tuesday before a meeting with Republican members of Congress.

The following day, however, Trump appeared to answer "no" to a reporter's question asking whether Russia was still targeting the U.S. While hours later, Press Secretary Sarah Sanders emerged to say Trump had merely tried to put a stop to the questioning by saying "no," although he continued discussing Russia after that.

Sunday night's tweet is likely to keep alive a controversy that has distanced Trump from aides and supporters alike.

"The evidence is overwhelming," Rep. Trey Gowdy, R-S.C., told "Fox News Sunday" hours before Trump's latest missive. "It can be proven beyond any evidentiary burden Russia is not our friend and they tried to attack us in 2016."

The most striking comments from a Trump adviser came Thursday, when Director of National Intelligence Dan Coats told the Aspen Security Forum that he wished the president had not met one-on-one with Putin. When Coats was informed by NBC News' Andrea Mitchell that Trump had invited Putin to Washington in the fall, he dramatically cupped his hand to his ear and told her: "Say that again." He then took a deep breath and continued: "OK. That's going to be special."

On Saturday, Coats issued a clarifying statement: "My admittedly awkward response was in no way meant to be disrespectful or criticize the actions of the president."

"The president either needs to rely on the people he has chosen to advise him or those advisers need to reevaluate whether or not they can serve in this administration," Gowdy said Sunday, "but the disconnect cannot continue when the evidence is overwhelming and the president needs to say that and act like it."

Fox News' Andrew O'Reilly and The Associated Press contributed to this report.