Kushner, who met behind closed doors with Senate Intelligence Committee staff, issued a written statement before that session that gave the fullest account to date of his contacts with Russian officials during the campaign and the presidential transition, Reuters said.

Kushner, like Trump a businessman, portrayed himself as someone who was new to politics when he became a top adviser to his father-in-law's campaign and was often so frantic fielding phone calls and emails that his recollections of some meetings was somewhat hazy.

"I did not collude, nor know of anyone else in the campaign who colluded, with any foreign government," he said. "I had no improper contacts. I have not relied on Russian funds to finance my business activities in the private sector."

The Senate Intelligence Committee is one of several congressional panels investigating the Russia matter, along with a federal criminal probe led by special counsel Robert Mueller.

Speaking at the White House after the meeting, Kushner said all of his actions were proper and occurred within a "very unique campaign."

Kushner said Trump prevailed over his Democratic rival Hillary Clinton in November 2016 because he ran a "smarter campaign" and that to suggest otherwise "ridicules those who voted for him.”

The Republican president, who has called the Russia probes politically motivated, lashed out at the investigations in Twitter messages on Monday. Trump has been dogged by allegations that his campaign aides worked with Russia, which U.S. intelligence agencies have accused of interfering in the election. Moscow has denied any meddling, and Trump says his campaign did not collude with Moscow.

Kushner arrived with prominent white-collar defense lawyer Abbe Lowell for the meeting with Senate staffers, which lasted about 2-1/2 hours.

Read alsoU.S. Attorney General met with Russian envoy twice last year, failed to disclose encounters - mediaIn his written statement, Kushner said he first met Russian Ambassador Sergei Kislyak in Washington in April 2016 and shook hands. He said he did not recall phone calls with Kislyak between April and November 2016, as reported by Reuters in May, had found no evidence of the calls in phone records and was skeptical they took place.