David Cameron will meet the presidents of Afghanistan and Pakistan this weekend as part of efforts to prevent a Taliban resurgence when British troops leave.
The Prime Minister will dine with Hamid Karzai and Asif Ali Zardari at his Chequers residence on Sunday, before hosting the first in-depth discussion with them and their top officials on Monday.
It is the third trilateral talks session they have held since the summer. UK officials believe the 2014 deadline for ending combat operations by British and US troops has concentrated minds in Pakistan.
Foreign ministers, Chiefs of Army Staff, Chiefs of Intelligence and the chairman of the Afghan High Peace Council are expected to attend, with discussions focusing on the peace process in the war-torn country.
A government spokeswoman said: "This trilateral process sends a very clear message to the Taliban: now is the time for everyone to participate in a peaceful political process in Afghanistan."