British Prime Minister David Cameron is hosting two days of talks with the leaders of Afghanistan and Pakistan to discuss the Afghan peace process.
The BBC reports the talks are aimed at improving co-operation between the two countries to promote regional stability.
For the first time the Afghan and Pakistani army and intelligence chiefs will also take part in the discussions.
Most international troops are scheduled to withdraw from Afghanistan by the end of next year.
In a process initiated by Mr Cameron last year, Afghan President Hamid Karzai and Pakistani President Asif Ali Zardari have agreed to work together on a framework of co-operation following the international troops' departure next year.
Mr Cameron will host a dinner with Mr Karzai and Mr Zardari at his official country residence Chequers north of London on Sunday evening.
He will then hold the in-depth talks with both presidents and their key officials on Monday.
"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," Downing Street said in a statement.
"As the prime minister has set out previously, a stable Afghanistan is not just in the interests of Afghans, but also in the interests of their neighbours and the UK."