By Jonathan Landay, Steve Holland and Yomna Ehab WASHINGTON/CAIRO, May 29 (Reuters) - Iran said on Friday it was looking for actions, not words from the United States after sources said President Donald Trump was weighing an initial U.S.-Iranian agreement to extend a ceasefire and open the Strait of Hormuz. The comments by Iran's top negotiator, Mohammad Baqer Qalibaf, were in line with previous defiant statements from Iran but added to questions over how such an agreement might unfold.