The U.S. "will be there" if Chile asks for rescue and recovery help after a powerful earthquake struck the South American nation, President Barack Obama said Saturday. He also warned people in Hawaii, Guam, American Samoa and the West Coast to heed the instructions of local authorities about evacuations and other measures in advance of a tsunami moving across the Pacific Ocean. External: The American Red Cross describes its role in the situation and provides tips on how to help Updated 3:58 p.m. Photos: Earthquake in Chile Updated 15 minutes ago