The January 6th Committee is debating if former US President Donald Trump and former Vice President Mike Pence should be called to testify. The panel had a closed-door meeting on Tuesday, however, no announcement has been made so far.

The committee does not expect that Trump or Pence would agree to testify before the House Select Committee but some members believe a formal invitation should be sent out, according to CNN reports citing unnamed sources. Such testimonies have been rare.

US Representative Bennie Thompson, the chair of the January 6th Committee, has said that testimony from the former Vice President will be welcome, the source told CNN. The January 6th Committee is expected to conclude its investigation in the coming months.

Some have questioned whether the committee needs to call Pence, who resisted Trump’s pressure to try and block Joe Biden’s certification on January 6, Associated Press reported.

The panel has been in discussions with Pence’s lawyers for months, without any discernible progress. Still, the committee could invite Pence for closed-door testimony or ask him to answer written questions.

Trump is also facing scrutiny in several other investigations, including at the Justice Department and over the classified documents he took to Mar-a-Lago, his private residence in Florida.

The panel has already interviewed more than 1,000 people, but lawmakers and staff are still pursuing new threads. The committee recently spoke to several of the Cabinet secretaries, including former Treasury Secretary Steven Mnuchin in July and former Secretary of State Mike Pompeo and former Transportation Secretary Elaine Chao in August.

The committee has also pursued an interview with conservative activist Virginia “Ginni” Thomas, who’s married to Supreme Court Justice Clarence Thomas. Lawmakers want to know more about her role in trying to help Trump overturn the election. She contacted lawmakers in Arizona and Wisconsin as part of that effort.