Mitchell's departure for the Middle East came as Obama gave his first television interview to an Arab broadcaster, pledging his administration would take a wider view of peace in the region.
Speaking to Al Arabiya, Obama said the US remains committed to protecting its long-time ally Israel, but also believed that there were Israelis who recognised the need for regional peace and would be willing to make the necessary sacrifices to achieve that.
"I think the most important thing is for the United States to get engaged right away," he said.
Commenting on Mitchell's visit to the Middle East he said: "What I told him is to start by listening ... because all too often the United States starts by dictating."
Obama acknowledged that sending Mitchell to the region would be no overnight success but added that he was "absolutely confident" of making genuine progress in the region's peace efforts through consistent and timely engagement.
In 2000, Mitchell led a fact-finding committee on Middle East violence that recommended commitments by Israel and the Palestinian Authority to immediately and unconditionally end their fighting.
"Conflicts are created, conducted and sustained by human beings. They can be ended by human beings"
US envoy for Middle East peace
His report, released in April 2001, urged Israel to freeze settlements in the West Bank and the Palestinians to cease rocket attacks across the border, the two issues that remain sticking points today.
Robert Wood, a spokesman for the US state department, said Mitchell might travel to the Gaza Strip, where Israel waged a 22-day war on Hamas, killing more than 1,300 Palestinians before reaching a fragile truce on January 18.
The new US administration will "actively and aggressively" seek a lasting peace between Israel and the Palestinians, he said, as well as Israel and its neighbours.
Wood said Mitchell will work to consolidate the Gaza ceasefire, help in preventing alleged arms smuggling by Hamas and facilitate the opening of border crossings.
Mitchell's report will also help formulate the new administration's overall policy toward the Middle East, Wood said.
Ziad Hafez, managing editor of the journal Contemporary Arab Affairs, told Al Jazeera that he doubts about whether Mitchell will achieve much in his new role.
"I don't think any movement is going to take place as long as the fundamental rules are not observed - which means that if you don't talk to the principal parties, nothing much will be accomplished," he said.
"Neither the Palestinian Authority nor the Egyptian government can provide any leverage over the situation in [Hamas-run] Gaza.
"Mitchell already had a previous mission in the Middle East and it did not amount to much, so I don't know what he will do now. As long as there is no political will in the United States to work seriously in promoting the Arab peace initiative [on Israeli-Palestinian relations], I don't think a lot will be accomplished."
Mitchell, 77, is credited with persuading all sides in the Northern Ireland conflict to sign up to a power-sharing deal, culminating in the landmark Good Friday peace accord in 1998.
At an earlier state department ceremony announcing his appointment, Mitchell recalled his role in producing the Northern Irish deal.
"In the negotiations which led to that agreement, we had 700 days of failure and one day of success," he said.
"For most of the time, progress was nonexistent or very slow. So I understand the feelings of those who may be discouraged about the Middle East."
Citing his experience, Mitchell said "there is no such thing as a conflict that can't be ended. Conflicts are created, conducted and sustained by human beings. They can be ended by human beings."