ISTANBUL  - Washington will monitor actions by Egyptian politicians and hold them "accountable," US Secretary of State Hillary Clinton said on Sunday, after the Muslim Brotherhood entered Egypt's presidential fray.

"We're going to watch what the political actors in Egypt do. We're going to watch their commitment to the rights and the dignity of every Egyptian," Clinton told reporters in Istanbul following a meeting of the "Friends of Syria" group.

"We will watch what all the political actors do and hold them accountable for their actions," she added when asked about the Brotherhood changing plans and announcing a candidate for the May 23-24 presidential vote.

The Muslim Brotherhood's political arm, the Freedom and Justice Party, said on Saturday it would nominate Khairat al-Shater, a professor of engineering and business tycoon, to contest Egypt's first presidential election since a popular uprising ousted Hosni Mubarak last year.

The Islamists, who control parliament, had repeatedly said they would not put forward a member for the election in order to mitigate fears that they were trying to monopolise power.

The Brotherhood's leadership insists that Shater's nomination is not an about turn, but a necessary measure in the face of latest developments. The Freedom and Justice Party has been pressuring the military to sack the cabinet - which it accuses of stalling the revolution - and to appoint a FJP-led government.

But the Supreme Council of the Armed Forces, which took power when Mubarak was ousted in February, 2011, has stood by the cabinet and has lashed out at the Islamists over their demand.

"We want to see Egypt move forward in a democratic transition, and what that means is you do not and cannot discriminate against religious minorities, women, political opponents," said Clinton, who did not mention the Brotherhood by name. "There has to be a process starting in an election that lays down certain principles that will be followed by whoever wins the election. That is what we hope for the Egyptian people."

She added that she "really" hoped the Egyptian people got what they staged their uprising for, "which is the kind of open, inclusive, pluralistic democracy that really respects the rights and dignity of every single Egyptian."