A member of the congressional caucuses on Vietnam and human rights lashed out at Hanoi for roughing up a U.S. diplomat who was attempting to visit a well-known dissident.

Christian Marchant, a political officer with the U.S. Embassy in Hanoi, was attempting to meet with Father Nguyen Van Ly, a democracy advocate being held under house arrest. Ly told Radio Free Asia that the diplomat was "wrestled down to the ground right in the middle of the road" in front of hundreds of witnesses.

"We are aware of and deeply concerned by the incident and have officially registered a strong protest with the Vietnamese government in Hanoi," State Department spokesman Mark Toner said Wednesday.

Rep. Ed Royce (R-Calif.), a member of the House Foreign Affairs Committee, said in a statement Friday that Marchant's legs were repeatedly slammed in a car door in violation of international laws protecting diplomats.

"This attack on a U.S. diplomat is beyond reprehensible," Royce said. "My staff has met with this political officer and can confirm that he is no threat to Vietnam. That, however, didn’t prevent his legs from being crushed by Vietnamese officials.

"In the past, the Vietnamese government has reserved the use of its thuggish tactics for peaceful dissidents and those deemed as threats to the government’s stranglehold on power. It’s now become clear that no one is immune from abuse," Royce added.

On the same day of the attack, Royce introduced H.R.156, the Vietnam Human Rights Sanctions Act, a bill that imposes sanctions on Vietnamese government officials who are complicit in human-rights abuses committed against the people of Vietnam. 

The bill resurrects an effort by former Rep. Joseph Cao (R-La.), who introduced the sanctions bill, co-sponsored by Royce and others, in November. 

Royce also introduced a bill Wednesday that calls on the State Department to list Vietnam as a "country of particular concern" in regard to religious freedom.

That bill has five co-sponsors: Reps. Zoe Lofgren (D-Calif.), Dana Rohrabacher (R-Calif.), Loretta Sanchez (D-Calif.), Chris Smith (R-N.J.) and Frank WolfFrank Rudolph WolfHouse votes to mandate sexual harassment training for members and staff Trump, global religious freedom needs US ambassador to lead Bottom Line MORE (R-Va.).

"It is widely understood that Vietnam has backslid on every human-rights front," said Royce. "This attack on a U.S. diplomat is further proof of why we need to make human rights discussions a top priority, and shows why we need to relist Vietnam as a ‘Country of Particular Concern’ for violations of religious freedom. Maybe this assault will convince the State Department to make that listing."