United States vice president-elect Joe Biden will lead a bipartisan Congressional delegation on a visit to Southwest Asia before he takes office alongside Barack Obama [Images] on January 20.

For security reasons, details of the trip and the countries to be visited have not been released. Biden would be accompanied by Senator John Kerry, the former Democratic Presidential candidate and the incoming Chairman of the powerful Senate Foreign Relations Committee.

Biden is the outgoing chairman of this powerful Senate committee, which plays a key role in shaping the US foreign policy.

Other members of the delegation are Democratic Senator Jack Reed and Republican Senators Susan Collins and Lindsey Graham.

"The purpose of this trip is fact-finding -- in the coming months both the executive and legislative branches will carefully review US policy toward this region, and the trip will allow its participants to bring current and first-hand information to these reviews," Biden's Senate spokeswoman Elizabeth Alexander said.

"The fact-finding delegation will make it clear to foreign leaders that they are not there to speak on behalf of the US government, or convey policy positions for the incoming administration," Alexander said.

Media reports from Islamabad [Images] said the delegation would be visiting Pakistan too, but there was no confirmation or denial by Biden's office. "For security reasons, details of the delegation's itinerary will be released as the trip progresses," Alexander told PTI in an email response.

However, given the tense situation in South Asia, it is widely speculated that Biden-Kerry delegation, during their trip to Pakistan, as reported, would take up the issue of Mumbai [Images] terrorist attack and try and defuse tension in the region.

Another statement issued by the office of Senator Kerry did not give any details of the countries to be visited by the US lawmakers.

"For security purposes, the details of the Congressional delegation's itinerary will be released throughout the week-long trip," it said.

Kerry had recently traveled to Pakistan, Afghanistan, Georgia and India in December. During his trip to the region, he had met Pakistan President Asif Ali Zardari [Images] and Indian

Prime Minister Manmohan Singh [Images].