The House Intelligence Committee is holding a rare Saturday session with the only White House official who has been willing to provide testimony on the schedule.
Mark Sandy, responsible for national security at the Office of Management and Budget, is expected to answer questions regarding why his agency temporarily withheld U.S. military aid from Ukraine, which is at the center of allegations against President Donald Trump.
The administration reportedly withheld about $400 million in lethal military aid Congress had authorized to help Ukraine defend against Russian aggression.
Sandy is providing testimony behind closed doors.
The military aid was not withheld for a lengthy period of time and was eventually delivered to the Ukrainian government. That aid included Javelin anti-tank missiles that the country had been requesting for some time.
No lethal military aid was provided to Ukraine during the Obama administration, though under provisions of the Budapest Memorandum signed in 1994, the U.S., Britain, and other European countries agreed to help defend Ukraine in exchange for returning a Soviet-era nuclear weapons stockpile to Russia.
Previous witnesses before the committee have testified that Trump instructed the aid to be withheld until the Ukrainian government agreed to announce an investigation into former Vice President Joe Biden and his son, Hunter Biden.
The president has discounted those allegations, pointing to a released transcript of a July phone call between him and Ukrainian President Volodymyr Zelensky, which revealed no such “quid pro quo” demand.
Other White House officials have instructed Democrat-run committees in the House they will ignore their subpoenas to testify on instructions from the Trump administration, at least until federal courts weigh in on the issue.
Two State Department officials who testified Wednesday, William Taylor and George Kent, discussed how they became aware of requests from Trump allies outside normal diplomatic channels that affected the aid for Ukraine.
Former NYC Mayor and presidential attorney Rudy Giuliani has been working on the Ukraine investigation on behalf of Trump, which has drawn the ire of career diplomats and foreign policy bureaucrats.
On Friday, former U.S. Ambassador to Ukraine Marie Yovanovitch testified that Giuliani’s work compromised American foreign policy with Ukraine.
However, under cross-examination by Rep. Jim Jordan (R-Ohio), Yovanovitch said she never questioned Ukrainian officials who were believed to have been assisting the 2016 Hillary Clinton campaign with its quest to find political dirt on Trump and his campaign associate, Paul Manafort.
Also Friday, House Intelligence Committee Ranking Member Devin Nunes (R-Calif.) likened Yovanovitch’s complaints about Giuliani and President Trump’s unconventional foreign policy approach to a “human relations” issue that should have been discussed by a subcommittee.