CAIRO — President Hosni Mubarak set up a committee today to recommend constitutional amendments to relax presidential eligibility rules and impose term limits — seeking to meet longtime popular demands as a standoff with protesters seeking his ouster enters its third week.

Mubarak’s decrees were announced on state television by Vice President Omar Suleiman, who also said that Mubarak will set up a separate committee to monitor the implementation of all proposed reforms. The two committees will start working immediately, he said.

The government has promised several concessions since the uprising began on Jan. 25 but has refused the protesters’ main demand that Mubarak step down immediately instead of staying on through September elections.

Today’s decision was the first concrete step taken by the longtime authoritarian ruler to implement promised reforms.

Mubarak’s efforts to stay in office got a boost from the Obama administration, which conceded that it will not endorse calls for the president’s immediate departure, saying a precipitous exit could set back the country’s democratic transition.

After several days of mixed messages about whether it wants to see Mubarak stay or go, Washington stepped up calls for a faster, more inclusive national dialogue on reform in Egypt.

Under Egypt’s constitution, Mubarak’s resignation would trigger an election in 60 days. U.S. officials said that is not enough time.

Mubarak also ordered a probe into last week’s clashes between the protesters and government supporters as well as mass detentions of human rights activists and journalists.

The committee will refer its findings to the attorney-general, Suleiman said.

Thousands of protesters, meanwhile, remained camped out in the central Tahrir Square, many hoping for an appearance by Google executive Wael Ghonim, a 30-year-old marketing manager who has emerged as a rallying point after he was released after 12 days in custody.

About 90,000 people have joined a Facebook group nominating Ghonim to be their spokesman.