State Department spokeswoman Jen Psaki told reporters during her regular press briefing Tuesday the U.S. government was following events in Turkey "with great concern."
The State Department said it was "very concerned" by the use of excessive force by police against demonstrators, but Psaki said a call for an investigation by Turkish President Abdullah Gul was welcome.
"We're hopeful that that will have an impact on the country and think that's a positive step," she said.
Tear gas was used to dispel protesters upset with plans to raze a small park in Istanbul. The Turkish government apologized for reports of police brutality.
The U.S. State Department issued a travel advisory in response to the unrest in Turkey. The advisory said there were "numerous reports of violence" and at least two deaths associated with conflict between demonstrators and Turkish police.
"The Turkish National Police and protesters continue to clash in some locations," the Tuesday advisory said. "Individuals caught in the vicinity of violence have been injured and/or detained, including U.S. citizens."
The State Department said there were no direct attacks on U.S. citizens in Turkey, however.