WASHINGTON

American nationals should immediately leave Russia and Ukraine, the State Department said Thursday, citing potential arrest by Russian security officials. 

"We are warning US citizens that the Russian government security officials in both Russia and in Ukraine, may be singling out US citizens based on their nationality," spokesman Ned Price said at a news conference.

Price remarks came one day after the agency issued a travel advisory for Americans to not travel to Russia because that country "may single out and detain U.S. citizens in Russia."

"Our updated travel advisories now reflect that information. We reiterate that all US citizens in Russia and Ukraine should depart immediately," Price added.  

Deadly attacks in Israel

Price reiterated US condemnation for deadly attacks in Israel that left more than 10 dead in three cities in one week.

"We urge those seeking to escalate tensions to cease their actions immediately. Retaliatory violence is also entirely unacceptable," said Price, calling for the protection of innocent lives of Israelis and Palestinians.

He said in April three major religions -- Muslims, Jews and Christians -- will be celebrating Ramadan, Passover and Easter, respectively, and added the US will do everything that "this holy month for these three religions is a peaceful one."