U.S. President's son Donald Trump Jr. and former Trump campaign chairman Paul Manafort will testify before the Senate judiciary committee on July 26.
President Trump's son-in-law Jared Kushner is also expected to appear before the Senate intelligence committee on Monday, reports CNN, adding that Kushner's testimony would be behind closed doors.
The development comes amid already intensive congressional investigations.
In June 2016, the President's eldest son agreed to meet with someone described as a "Russian government attorney" after receiving an email offering him "very high level and sensitive information" that would "incriminate" Democratic presidential nominee Hillary Clinton, according to emails Trump Jr. publicly released last week.
Both Manafort and Kushner attended that meeting on June 16th.
"As Mr. Kushner has been saying since March, he has been and is prepared to voluntarily cooperate and provide whatever information he has on the investigations to Congress. Working with and being responsive to the schedules of the committees, we have arranged Mr. Kushner's interview with the Senate for July 24. He will continue to cooperate and appreciates the opportunity to assist in putting this matter to rest," said Kushner's lawyer Abbe Lowell.