US Secretary of State John Kerry and EU's foreign policy chief Catherine Ashton lamented the "limits" of their role, after envoys from the two sides, Qatar and the United Arab Emirates failed in their 10-day efforts to diffuse the Egyptian crisis ensuing from the military's ouster of elected President Mohamed Morsi on July 3.

　　"Today, the diplomatic efforts ended," Egypt's interim President Adly Mansur said Wednesday in a statement.

　　Ashton herself travelled to Egypt in late July and met with Morsi who remained in detention. US Republican Senators John McCain and Lindsey Graham joined William Burns, Kerry's deputy, in the mediation efforts.

　　"While further violent confrontations have thus far been avoided, we remain concerned and troubled that government and opposition leaders have not yet found a way to break a dangerous stalemate and agree to implement tangible confidence-building measures," Kerry and Ashton said in a joint statement.

　　"The Egyptian government bears a special responsibility to begin this process to ensure the safety and welfare of its citizens," they added.

　　Nearly 300 people have been killed in violence since Morsi's removal, and his Islamist supporters are still encamped in two squares in Cairo - Rabaa al-Adaweya in Nasr City and Nahdet Misr in Giza, demanding his reinstatement.

　　The Egyptian interim government instructed its security forces in late July to end the sit-ins, raising the specter of more deadly confrontations. Egypt's interim Prime Minister Hazem al- Beblawi reiterated a similar call on Wednesday.

　　"This remains a very fragile situation, which holds not only the risk of more bloodshed and polarization in Egypt, but also impedes the economic recovery which is so essential for Egypt's successful transition," Kerry and Ashton said.

　　"Now is not the time to assess blame, but to take steps that can help initiate a dialogue and move the transition forward," they declared.

　　Diplomatic efforts in Egypt have focused on promoting a reconciliation process between the government and the opposition parties, including the Muslim Brotherhood to which Morsi belongs, and moving toward amendments to the constitution as well as parliamentary and presidential elections in an inclusive way.