U.S. Defense Secretary Robert Gates, arriving in Iraq on an unannounced visit Thursday, said he plans to tell Iraqi leaders that the U.S. commitment for a military buildup in the country is not open-ended. Speaking to reporters in Israel just before a quick flight to Baghdad, Gates said the ongoing debate in Washington about financing the military presence in Iraq has sent the message that both the U.S. government and the American public are running out patience with the war, according to a report of the Associated Press.