Defense Minister Ehud Barak on Thursday told the visiting U.S. envoy to the Middle East, George Mitchell, that the time had come to advance the Israeli-Palestinian peace process.

"The time has come to move forward to start the process and pass all of the obstacles, because this will help everyone," Barak said at the start of the meeting, according to a statement he released. "No obstacle is impassable."

A former senator and key player in brokering the Northern Ireland peace deal, Mitchell returned to Israel on Wednesday for further talks with both sides aimed at kick-starting negotiations.

Barak added: "We need to begin real negotiations on an accord between us and the Palestinians while protesting the security interests of Israel, which will enable the realization of the solution of two states for two people."

The defense minister also said Israel was a "partner" in U.S. President Barack Obama's peace initiative for a comprehensive peace agreement in the Middle East, and wished to work toward a two-state solution as soon as possible.

In Washington, State Department spokesman Ian Kelly said Thursday that restarting negotiations is an urgent matter. The time has come for both sides o agree to just cut right through all of this and get back to peace talks, he aid.

Mitchell hopeful Israel-PA peace talks can resume soon

Earlier Thursday, Mitchell told President Shimon Peres on Thursday that he is hopeful that peace talks between Israel and the Palestinians can be restarted soon, and that Obama is committed to bringing peace to the region.

"We're going to continue with our efforts to achieve an early relaunch of negotiations between Israelis and Palestinians," Mitchell told reporters before a private meeting with Peres in Jerusalem.

He added this was an "essential step" toward achieving comprehensive peace in the region.

A senior U.S. official told Israeli reporters that Mitchell's visit was not likely to conclude with an announcement of a renewal of talks, and that further meetings would be necessary. Israeli sources, however, told Haaretz that an announcement on renewing negotiations was "within reach."

On Friday, Mitchell will meet with Prime Minister Benjamin Netanyahu, and over the weekend he will travel to Ramallah to meet with Palestinian President Mahmoud Abbas.

The U.S. official said Obama had instructed Secretary of State Hillary Clinton and Mitchell to report to him by mid-October on progress.

"We do not foresee a breakthrough on this visit, but we have a sense of urgency and we are determined to make progress," the official said. "The president is impatient with the current situation and expects the sides to move forward."

Lieberman: Years before peace deal

Mitchell's optimism was not reflected by Israel's foreign minister, however, who said Thursday that there was no chance of ending the Israeli-Palestinian conflict for many years, and that efforts to reach a final peace deal have failed since the first accord in 1993.

Speaking to Israel Radio, Lieberman said he believes it is unrealistic to think a long-term agreement on ending the conflict can be reached at this time and that whoever thinks an agreement can be reached soon just doesn't understand the situation.

He said both sides should instead strive for interim agreements that would create stability and leave the tough issues between the them "to a much later stage."

"I will tell [Mitchell] clearly, there are many conflicts in the world that haven't reached a comprehensive solution and people learned to live with it," Lieberman told the radio.

"But together with this, people made the most dramatic decision. To give up using force. To give up terror. And to stop inciting against one another," he said.

"What is possible to reach is a long-term intermediate agreement ... that leaves the tough issues for a much later stage," Lieberman said, referring to contentious issues such as the future status of Jerusalem, Palestinian refugees and borders.