Today, the Egyptian military command signaled that the days of Hosni Mubarak are over.

CAIRO — The command of Egypt’s military stepped forward Thursday in an attempt to stop a three-week-old uprising, declaring on state television it would take measures “to maintain the homeland and the achievements and the aspirations of the great people of Egypt” and meet the demands of the protesters. The development appeared to herald the end of President Hosni Mubarak’s 30-year rule.

Several military leaders and officials in Mr. Mubarak’s government indicated that the president intended to step down on Thursday. Some reports said he aimed to pass authority to his hand-picked vice president, Omar Suleiman, but what role Mr. Suleiman would play in a military government, if any, remained uncertain.

State television said Mr. Mubarak will appear tonight with an announcement.