Mitchell, who is set to come to Israel later Sunday, said that the US was committed to a dialogue based on mutual respect and shared interests, adding that US President Barack Obama was "determined" to forge an agreement between Israel and the Arab world.
Mitchell described his talks with Assad as "very candid and positive", saying he discussed with the Syrian leader "the prospects for moving forward on our goal of comprehensive peace in the region and improved bilateral relations between Syria and the United States.
"I told President Assad that President Obama is determined to facilitate a truly comprehensive Arab-Israeli peace," he said. "That peace means between Palestinians and Israelis, between Syria and Israel, and between Lebanon and Israel.
"And of course, ultimately, the full normalization of relations between Israel and all of the countries in the region. This is what the Arab peace initiative calls for, and it is the ultimate aim of the effort we are undertaking," Mitchell said.
At the opening of the weekly cabinet meeting Sunday, Prime Minister Binyamin Netanyahu commented on the upcoming arrival of Mitchell and three very senior US foreign policy and security figures being dispatched to Israel, saying the visit was routine and not indicative of a rift in the relations between the two countries.
"These visits are being held as part of the diverse relationship between Israel and the US, a relationship that existed in the past and continues to exist today," Netanyahu said.
"Naturally, even within the fabric of friendly relations between allies there are points over which there is not full agreement," the prime minister continued. "We are trying to arrive at agreement so that we can promote our objectives: peace, security and prosperity for the entire Middle East."
However, both Jerusalem and Washington have lowered expectations for any major breakthrough on the settlement construction issue, despite the upcoming visit to Israel of the administration's Middle East "A-Team".
"I don't know how much more effort it is going to take to reach common ground with the US," a senior government source said Saturday night, on the eve of Mitchell's arrival.
Mitchell's arrival will be followed on Monday by a brief visit - believed to be for only six hours - by US Defense Secretary Robert Gates. He is expected to focus his talks on Iran, as well as bilateral US-Israeli security issues.
And on Wednesday, US National Security Adviser Jim Jones will lead a large team of National Security Council officials, including new Middle East point man Dennis Ross, for talks with National Security Adviser Uzi Arad and his staff.
Herb Keinon contributed to this report