Western and Arab envoys visited a high-ranking member of Egypt's Muslim Brotherhood in jail on Monday, the state news agency MENA reported, to press an international bid to defuse the crisis ignited by President Mohammed Morsi's downfall.

The envoys met deputy Brotherhood leader Khairat El-Shater just after midnight, having received permission from the prosecutor general to visit him at Tora prison, south of Cairo, the state news agency reported.

The report citing "an informed source" contradicted an earlier government denial of a visit by the envoys from the United States, European Union, United Arab Emirates and Qatar.

MENA gave no further details. Earlier, the Doha-based Al Jazeera news channel reported the meeting had taken place. The reports could not be independently confirmed.

Shater is deputy leader of the group that propelled Morsi to office last year in Egypt's first democratic presidential election. Seen as the Brotherhood's main political strategist, he was arrested after Morsi's downfall on charges of inciting violence.

The international mediation effort is helping to contain the conflict between Morsi's Islamist backers and the interim government installed by the military that overthrew him on July 3, following mass protests against his rule.

The army-backed government said on Sunday it would give mediation a chance but warned that time was limited.

Thousands of Morsi supporters remain camped out in two Cairo sit-ins, which the government has declared a threat to national security and pledged to disperse.

The authorities say the Brotherhood has incited violence, accusing it of engaging in terrorism - a charge the movement denies as it grapples with one of the toughest moments in its 85-year history.

The crisis has left Egypt, the Arab world's biggest nation, more dangerously divided than at any point since the downfall of U.S.-backed strongman Hosni Mubarak in 2011 and raised questions over the future of its nascent democracy.

Morsi became Egypt's first freely elected leader in June 2012. But fears that he sought to establish himself as a new dictator coupled with a failure to ease economic hardships afflicting most of its 84 million people led to huge street demonstrations on June 30, triggering the army move.

The military has laid out a plan that could see a new head of state elected in roughly nine months. The Brotherhood, an Islamist movement that spent decades in the shadows before Mubarak's downfall, says it wants nothing to do with the plan.

However, diplomats say the group knows Morsi will not return as president and wants a face-saving legal formula for him to step down that guarantees it a stake in the political future.

Almost 300 people have been killed in political violence since Morsi's overthrow, including 80 shot dead by security forces in a single incident on July 27. Much of the Brotherhood's leadership is in custody.

On Sunday, a Cairo court announced that the top leader of the Brotherhood and two other officials including Shater would go on trial in three weeks' time for crimes including incitement to murder during protests in the days before Morsi was toppled.

That could complicate efforts to launch a political process, encourage national reconciliation and avert further bloodshed.

The interim administration has said it wants political reconciliation to include the Brotherhood but says the group must first renounce and halt violence.

Suggesting an appetite for compromise, a spokesman for the Morsi camp said on Saturday it wanted a solution that would "respect all popular desires," an apparent recognition of the strength of the protests against his one year in power.

During a meeting with U.S. Deputy Secretary of State William Burns and European Union envoy Bernadino Leon on Saturday, the pro-Morsi delegation also said they would be willing to negotiate with politicians that backed Morsi's ouster.

But they are also seeking the restoration of a constitution suspended when Morsi was deposed and want the military, together with army chief General Abdel Fattah al-Sisi, out of politics.

Morsi is being held at an undisclosed location and facing a probe into accusations including murder.

In the United States, which supplies Egypt with $1.5 billion in aid each year, U.S. Senator Lindsey Graham said the Egyptian army must move "more aggressively" to hold elections. He said future U.S. aid will hinge upon a return to civilian rule.

U.S. President Barack Obama has asked Graham and Senator John McCain to travel to Egypt to meet members of the new government and the opposition.

"The military can't keep running the country. We need democratic elections," Graham said in a CNN interview.

Washington has been grappling with how to respond to the situation in Egypt, for decades an important ally in its Middle East policy.

"I want to keep the aid flowing to Egypt, but it has to be with the understanding that Egypt is going to march toward democracy, not toward a military dictatorship. And that's the message we're going to send," Graham said.