WASHINGTON — Senate Democrats privately pressed the FBI to determine whether Attorney General Jeff Sessions failed to disclose a third meeting with Russian ambassador Sergey Kislyak during a April 2016 campaign event for then-presidential candidate Donald Trump at Washington’s Mayflower Hotel, according to an aide to Vermont Sen. Patrick Leahy.

Leahy and Sen. Al Franken, D-Minn., requested the review earlier this year after Sessions belatedly disclosed two other meetings with Kislyak following Sessions’ January confirmation hearing in which the then-attorney general nominee said he was unaware of any such contacts, Leahy spokesman David Carle said Wednesday.

Franken said on MSNBC late Wednesday night he expects to hear back from the FBI on the status of this review shortly.

Sessions later amended his January testimony following disclosures in The Washington Post that he had met with the ambassador in July at the Republican National Convention and in September in the Washington office of the then-Alabama senator.

Facing a storm of criticism about his failure to disclose the two encounters, Sessions recused himself in March from any involvement in the FBI’s inquiry into Russia’s interference in the 2016 election.

Oversight of the inquiry, which also includes whether Trump campaign associates colluded with Russian officials, was passed to Deputy Attorney General Rod Rosenstein, who earlier this month appointed special counsel Robert Mueller to manage the widening Russia investigation.

Late Wednesday, CNN reported that congressional investigators conducting parallel probes into Russian interference also were reviewing a possible undisclosed April meeting between Sessions and Kislyak at the Mayflower.

Justice officials late Wednesday strongly denied any such contact between Sessions and Kislyak.

“The facts haven't changed,’’ Justice spokeswoman Sarah Isgur Flores said. “Then-Senator did not have any private or side conversations with any Russian officials at the Mayflower Hotel.’’

Carle said Wednesday that the FBI had not yet responded to questions posed by Leahy and Franken in letters sent by the lawmakers in March, April and May.