WASHINGTON — Egypt’s military rulers privately signaled a retreat on Friday in a crackdown on organizations that promote democracy and human rights, senior American officials said, even as the authorities in Cairo tried to discredit the organizations with accusations of suspicious activity.

The country’s de facto leader, Field Marshal Mohamed Hussein Tantawi, and other senior officials pledged to halt the raids against the organizations, to allow them to reopen their offices and to return documents, computers and other property seized on Thursday, the American officials said.

Field Marshal Tantawi offered the assurances during a 25-minute telephone conversation on Friday with the American defense secretary, Leon E. Panetta. The conversation capped a flurry of diplomatic protests over the shutdown of the groups and unusually sharp public criticism from the United States and Europe.

While the Egyptian government did not confirm that it would halt the raids, the swift, high-level intervention by Obama administration officials in Cairo and in Washington and by European officials underscored the seriousness of the diplomatic affront the raids had caused and their potential to sour relations significantly if they continued.