The U.S. State Department says Secretary Colin Powell has canceled a trip to Athens to attend the Olympics closing ceremony because of urgent business in Washington.

A State Department spokesman said events in Sudan and Iraq require Mr. Powell's close attention. He said anti-American protests in the Greek capital played no role in the Secretary's decision. The announcement came hours after police in Athens used tear gas to disperse at least 1,000 protesters, who shouted slogans critical of the U.S.-led war in Iraq. Later, a huge banner saying "Powell Go Home" was draped on the Acropolis hillside overlooking the city.

Greek officials said the U.S, Secretary will visit Athens in October.