Washington (CNN) Senate Majority Leader Mitch McConnell on Friday strongly condemned the Trump administration's decision to withdraw US troops from northern Syria, calling it a "grave strategic mistake" in a blistering op-ed.

McConnell's public criticism of the Trump administration is rare, but he has been vocally opposed to the President's decision to withdraw US troops from Syria following an October phone call with Turkish President Recep Tayyip Erdogan. Some lawmakers have made that opposition clear during phone calls with Vice President Mike Pence's office, according to a source familiar with the phone calls. And an official told CNN Pence phoned McConnell on his flight back from Ankara after brokering a brief ceasefire between Turkey and Syria.

In a statement to CNN on Saturday, McConnell spokesman David Popp said the op-ed "had nothing to do with his conversation with Vice President Pence."

But the conversation did not keep the GOP leader from penning that op-ed published in The Washington Post on Friday, ripping the President's decision to withdraw from Syria -- without naming him. Popp declined to provide details of McConnell's call with Pence.

McConnell warned that the withdrawal of US troops from Syria "will leave the American people and homeland less safe, embolden our enemies, and weaken important alliances."