“Abandoning this fight now and withdrawing U.S. forces from Syria would re-create the very conditions that we have worked hard to destroy and invite the resurgence of ISIS,” McConnell said. “And such a withdrawal would also create a broader power vacuum in Syria that will be exploited by Iran and Russia, a catastrophic outcome for the United States’ strategic interests.”

Following Trump’s announcement to withdraw U.S. troops from the region, Turkey went into northeastern Syria, a Kurdish-occupied region.

McConnell, who did not mention Trump by name, said Monday that the withdrawal of troops would not help the U.S.'s long-term interest in the region. He reiterated that earlier this year a bipartisan supermajority of senators supported legislation warning against the early withdrawal of U.S. troops from Syria and Afghanistan.

Trump received rare Republican blowback last week when he announced his decision to withdraw U.S. troops from Syria, following a conversation with Turkish President Recep Tayyip Erdogan, In response, McConnell urged Trump to “exercise American leadership.," while Sen. Lindsey Graham (R-S.C.), a close Trump ally, called the decision a "disaster in the making." Graham has introduced a sanctions bill against Turkey with Sen. Chris Van Hollen.

But Graham offered a contrasting tone to McConnell's Monday evening, after joining Trump at the White House to speak with Turkish officials and General Mazloum Kobani, the leader of the Kurdish forces. Graham praised the president for "trying to end the bloodshed through a negotiations deal addressing Turkey's concerns abut certain Kurdish elements near their border" and called on Democrats and Republicans to support Trump's executive order imposing sanctions on Turkish officials.

The South Carolina Republican said Trump warned Turkey that an attack on Kobani, a Kurdish enclave, "would be an international outrage that could not stand" and assured General Mazloum Kobani he would do "everything possible" to stop the Turkish incursion.

“The President’s team has a plan and I intend to support them as strongly as possible, and to give them reasonable time and space to achieve our mutual goals," Graham said.

Graham's visit to the White House came after a conversation with Speaker Nancy Pelosi (D-Calif.). Pelosi tweeted that the two were working together on a bipartisan resolution that would overturn Trump's decision to withdraw troops from Syria.

Despite Trump's executive order Monday, Senate Democrats say that sanctions against Turkey are not enough.

"Strong sanctions, while good and justified, will not be sufficient in undoing that damage nor will it stop the consequences stemming from the ISIS jailbreak," said Senate Minority Leader Chuck Schumer (D-N.Y.), in a joint statement with Sens. Bob Menendez (D-N.J.) and Jack Reed (D-R.I.). "The first step when Congress returns to session this week is for Republicans to join with us in passing a resolution making clear that both parties are demanding the president’s decision be reversed."

The senators further urged Trump to change course, calling the withdrawal of troops "a grave mistake worth reversing."