Senate Minority Leader Chuck Schumer and other top Democrats are sending a letter to President Donald Trump on Thursday demanding he develop and brief Congress on a plan to stop the Islamic State from returning in Syria now that most of the American forces have been pulled out of the country.

The letter comes as Trump plans to meet Turkish President Recep Tayyip Erdogan at the White House next week.

“Given the dynamics in northern Syria following your reckless decision to withdraw troops and permit Turkey’s invasion, and the continued threat posed by ISIS, we ask that you submit to Congress a comprehensive plan for Syria not later than December 6, 2019,” the letter reads.

The full Senate was briefed Oct. 30 on the situation in Syria and on the operation that resulted in the death of the terrorist group's leader, Abu Bakr al-Baghdadi, following a briefing to the full House the same day. Senators in attendance were shown videos of the raid that the Department of Defense later released to the press.

“It is clear that ISIS continues, they are not vanquished, they are not over,” Schumer, D-N.Y., told reporters after that briefing. “I believe that the administration has to do more to make sure the existing ISIS prisoners are guarded, to track down those who have escaped, and to have a far more concrete plan on how we deal with ISIS in the future.”

The Thursday letter asks the Trump administration to report to Congress on the number of known ISIS fighters remaining in Syria and the number of prisoners who were released and are still missing, and to provide a “plan to stabilize areas formerly controlled by ISIS, including efforts to support, develop, and expand local governance structures.”

Some lawmakers have expressed disappointment with Trump for inviting Erdogan to the White House.

“I can tell you, after what's happened in Syria with Erdogan, and the Turks going after our allies and friends the Kurds, I don't think this is the right moment in history for him to be a celebrated visitor to the White House,” Senate Minority Whip Dick Durbin, D-Ill., told reporter Wednesday after Trump announced the visit.