The United States is part of the diplomatic group, known as the Middle East Quartet, which, also made up of the United Nations, the European Union, Russia and the United States launched a roadmap for peace in 2003 that calls for an independent Palestinian state living in peace with a secure Israel.

Israeli Prime Minister Benjamin Netanyahu (L) shakes hands with Palestinian National Authority Chairman Mahmoud Abbas (R) as U.S. Secretary of State Hillary Clinton looks on during the launching ceremony of the direct negotiation between Palestine and Israel at the U.S. State Department in Washington D.C., the United States, Sept. 2, 2010. [Wang Chengyun/Xinhua]

At the same time, Mitchell acknowledged that the negotiations ahead are not easy, echoing the Wednesday statement by President Obama that "Hard work is only beginning."

"There are those who will use violence to try to derail these talks. There are going to be difficult days and many obstacles along the way," Mitchell said. "We recognize this is not an easy task. But as the (U.S.) president told the leaders, we expect to continue until our job is complete and successful. "

Speaking at the ceremony, chaired by Clinton, to relaunch the direct talks, Abbas said: "We know how hard it is in the negotiations ahead. What is encouraging is that the road is very clear."

For his part, Netanyahu said that the direct talks should lead to "truce concessions from both sides."

The new round of direct talks was held against the backdrop that Abbas has said that a peace agreement with Israel can be reached within one year while Netanyahu stated that a peace agreement would be difficult but "possible."

There are many obstacles to success, most immediately among them the looming Sept. 26 expiration of a 10-month Israeli moratorium on construction in West Bank settlements. Palestinians see such construction as a key obstacle to statehood, the observers said.