U.S. special Mideast envoy George Mitchell wrapped up a visit to the Middle East on Sunday after a weekend of meetings with top regional officials, but little in the way of breakthroughs.

He was back in Jerusalem on Sunday to try to get peacemaking moving again, with the Nobel Peace Prize award to President Barack Obama over the weekend adding new pressure to his mission.

Mitchell met Prime Minister Benjamin Netanyahu on Sunday for a second time, after holding a preliminary meeting on Friday prior to a visit to Cairo.

"It has been and remains an important objective of American policy and of President Obama and the secretary of state personally to achieve comprehensive peace in the Middle East," Mitchell told reporters in Cairo, before traveling to Jerusalem for his second meeting with Netanyahu.

"We understand that there are many difficulties, that there are many obstacles. But we are determined and committed to continue our efforts until that objective is reached," he said.

A laconic statement from the office of Prime Minister Benjamin Netanyahu said he and Defense Minister Ehud Barak met with Mitchell to continue talks to advance the peace process. Lower-level Israeli officials are to travel to Washington this week for further discussions, it added.

Mitchell met with Netanyahu and Palestinian President Mahmoud Abbas late last week before traveling to Cairo over the weekend to meet with Egyptian officials who play leading roles in mediating the conflict.

The U.S. envoy is dealing with adversaries whose positions haven't softened despite months of shuttle diplomacy. Israel refused to succumb to U.S. pressure to freeze settlement construction, and the Palestinians say they will not resume talks without that freeze.

Abbas will be hard-pressed to back down on that demand after provoking unprecedented outrage among his people for suspending efforts to bring Israel before a Gaza Strip war crimes tribunal.

Obama made a personal push last month to jump start the stalled talks with a three-way meeting with Netanyahu and Abbas. But there has been no visible progress toward reviving a moribund peace process on which Obama has staked Washington's credibility and his own.

The U.S. president was awarded the Nobel Peace Prize on Friday for his initiatives to reduce nuclear arms, ease tensions with the Muslim world and stress diplomacy and cooperation rather than unilateralism.

Since his appointment in January, Mitchell, 76, has visited Israel and the West Bank nine times.