Democrats in the US House of Representatives on Monday called on Secretary of State Mike Pompeo and Defense Secretary Mark Esper to provide witnesses for a hearing on Afghanistan policy, and threatened to issue subpoenas if their departments did not comply.

In letters to the pair, Democrats on the House Oversight and Reform Committee�s subcommittee on national security said the State Department and Pentagon have ignored for more than a year invitations to send witnesses or responded with delay, obfuscation and excuses for not providing them.

They said they would subpoena witnesses for a Sept. 9 hearing if the departments failed to confirm their participation by Wednesday.

The subcommittee will have no other choice but to receive testimony through compulsory process, they wrote.

The State and Defense departments did not immediately respond to requests for comment.

The United States and the Taliban signed a Feb. 29 accord for a conditions-based pullout of all US forces by May 2021, with the level dropping to 8,600 by this June. It also called for intra-Afghan peace talks that have been delayed by wrangling between the Taliban and Kabul.

The Democrats noted that President Donald Trump recently said he planned to cut US troops to no more than 4,000 by the Nov. 3 US election, and they expressed concern the reduction is politically motivated.

They cited US military and UN reports that said the Taliban have not severed links with al Qaeda as the Feb. 29 accord required. They also noted that the US commander in Afghanistan, Army General Kenneth McKenzie, said on June 10 that conditions for a full US withdrawal had not been met.

Meanwhile, the top Democrat on the Senate Foreign Relations Committee, Bob Menendez, said in a statement that he expected the State Department to brief Congress on recent Taliban attacks on US forces that constituted a clear violation of the Feb. 29 accord.