Turkish President Recep Tayyip Erdogan watched his security detail attack protesters outside Turkey's embassy to the United States on Tuesday.

The video, published by the U.S.-backed Voice of America's Turkish Service, shows Erdogan's vehicle parked outside of the embassy as the protest unfolded. It provides a clear but limited view of at least two burly, jacketed men beating protesters. As police sirens approach, Erdogan gets out the vehicle, buttons his suit jacket and walks into the Turkish embassy. The incident has outraged some American leaders.

"I'd throw the Turkish ambassador out [of the country]," Senate Armed Services Chairman John McCain told MSNBC.

Turkish Ambassador Serdar Kilic was summoned to the State Department for a personal rebuke on Wednesday, following a public condemnation of the violence by Secretary of State Rex Tillerson's spokeswoman.

"Violence is never an appropriate response to free speech, and we support the rights of people everywhere to free expression and peaceful protest," State Department spokeswoman Heather Nauert said Wednesday. "We are communicating our concern to the Turkish government in the strongest possible terms."

Erdogan has taken an array of authoritarian steps in recent months, following a failed coup attempt in July 2016, jailing more journalists than any other country and pushing through a constitutional referendum that expanded his power.

"The United States must be candid and consistent in our support of democratic values and respect for human rights for the sake of Turkey's future and our long-term interests in the region," Sen. Marco Rubio, R-Fla., and Sen. Bob Menendez, D-N.J., wrote in a letter signed by 15 colleagues. "We therefore urge you to make support for Turkish democracy and human rights a priority, both in your meetings with President Erdogan next week and in U.S. policy toward Turkey thereafter."

Trump didn't make any such criticism public, as his team is trying to ease a fraught U.S.-Turkey relationship at a time when Turkey could play a critical role in the fight against the Islamic State or drift closer to Russia, despite being a NATO ally.

"In some circumstances, if you condition our national security efforts on someone adopting our values, we probably can't achieve our national security goals or our national security interests," Tillerson said while discussing foreign policy principles with State Department staff. "If we condition too heavily that others must adopt this value that we've come to over a long history of our own, it really creates obstacles to our ability to advance our national security interests."