"The conduct of Turkish security personnel earlier this week is deeply disturbing," the official said. "The State Department has raised its concerns about these events at the highest levels and a thorough investigation that will allow us to hold the responsible individuals accountable is of the utmost importance to us."
The official also confirmed that two members of President Recep Tayyip Erdogan's security detail "were briefly detained during the altercations and subsequently released" and returned to Turkey with Erdogan.
"Customary international law affords heads of state and members of their entourage with inviolability from arrest and detention," the official said. "The United States recognizes this inviolability, which provides reciprocal protection for the United States abroad."
Several lawmakers have joined a growing chorus of voices demanding action in the wake of the bloody brawl that sent nine to the hospital on Tuesday -- just hours after Erdogan met with President Donald Trump at the White House.
Arizona Sen. John McCain, the Republican chairman of the armed services committee, called for the Turkish ambassador to the US to be thrown out of the country on Thursday.
"We should throw the Turkish ambassador out of the country, we should identify those people that performed these unlawful acts of beating people up and they should be charged," McCain told reporters.
McCain and his Democratic colleague Sen. Dianne Feinstein of California also wrote a letter to Erdogan condemning the violence.
The State Department told CNN on Thursday that it is "working closely with the local authorities concerning this incident," but declined further comment as the investigation is ongoing.
The Turkish embassy claimed the groups that assembled were "affiliated with the PKK (Kurdistan Workers Party)" without permission and "began aggressively provoking Turkish-American citizens who had peacefully assembled to greet the President," according to a statement released late Wednesday.
"The Turkish-Americans responded in self-defense," the statement from the Turkish embassy said. "We hope that, in the future, appropriate measures will be taken to ensure that similar provocative actions causing harm and violence do not occur."