The British prime minister Mr Tony Blair is to urge India and Pakistan to pull back from the brink of war during a diplomatic mission to the region.
He is expected to meet Indian prime minister Mr Atal Behari Vajpayee before travelling to meet Gen Pervez Musharraf in Pakistan.
Downing Street refuses to discuss details of the Premier's forthcoming travels because of security concerns.
Mr Blair's visit comes amid international concern that relations between the two countries are at their worst for decades.
Tensions have risen following the suicide bombing of the Indian parliament by Kashmiri separatists, said to be based over the border.
A government source described Mr Blair's trip as "very timely visit", adding: "The Prime Minister will call for restraint on both sides and will ask for dialogue - he will not have any pre-prepared blueprint."
Mr Blair is said to be working closely with US president Mr George W Bush in a bid to cut through the mounting tension.
The crisis has reportedly hit the anti-terror operations in Afghanistan as well as risking all-out war between the two countries.
Pakistani troops involved in the hunt for Osama bin Laden have apparently been redeployed along the Indian border.
PA