A bipartisan group of House lawmakers is urging President Donald Trump to cancel a planned White House visit by Turkish President Recep Tayyip Erdoan on Wednesday.

In a letter signed by two House Republicans and 15 Democrats , including House Foreign Affairs Chairman Eliot Engel (D-N.Y.), the lawmakers said Erdoans decision to invade northern Syria last month has had disastrous consequences for U.S. national security, has led to deep divisions in the NATO alliance and caused a humanitarian crisis on the ground.

Given this situation, we believe that now is a particularly inappropriate time for President Erdoan to visit the United States, and we urge you to rescind this invitation, the lawmakers wrote.

The White House did not immediately respond to a request for comment.

The letter, dated Nov. 8, also referenced Erdoans decision to purchase the Russian S-400 system, which the U.S. had warned was not compatible with NATO forces and could serve to aid Russian intelligence.

Trumps national security adviser, Robert OBrien, also said Sunday that the White House was very upset about Turkeys purchase of the Russian S-400 system. He said Trump would confront Erdoan about the purchase, as well as the ongoing allegations of war crimes and ethnic cleansing by Turkey, during their meeting Wednesday.

Were very concerned about those issues, the war crimes issues, OBrien told CBSs Face the Nation.

Were watching them. Were monitoring it very closely, he said. There is no place for genocide, for ethnic cleansing, for war crimes in the 21st century. The U.S. wont stand by for it, and weve made that position very clear to the Turks.

Secretary of State Mike Pompeo also said Monday that Trump would be discussing Turkeys invasion of Syria with Erdoan on Wednesday and would push for an outcome that protects all of those in Syria.

We will talk about what transpired there and how we can do our level best collectively to ensure the protection of all of those in Syria, not just the Kurds, but everyone in Syria, Pompeo said Monday, according to The Hill .

Trump ordered the withdrawal of U.S. troops from northern Syria in October, a decision that was met with widespread, bipartisan condemnation . The Turkish military swiftly invaded the region and began attacking Kurdish forces , which had been allied with the U.S. in the battle against the self-described Islamic State.

As retaliation for the invasion, Trump signed an executive order imposing sanctions and visa bans on top Turkish officials. He said he had also increased tariffs on Turkish steel imports and would halt negotiations on a major trade deal with the country.