David Cameron will travel to Turkey tomorrow for talks on how to deal with the threat from Islamic State (IS).
The Prime Minister will meet Turkish counterpart Ahmet Davutoglu and president Recep Tayyip Erdogan on his visit to Ankara.
Downing Street said the discussions would seek to build on existing counter-terrorism co-operation.
The US and the EU have been encouraging Turkey to take a more active role in tackling IS on its borders with Syria and Iraq.
There have also been calls for more help in tracking Britons travelling to the region to fight.
Mr Cameron will hold talks with Mr Davutoglu tomorrow, before they are joined by Mr Erdogan for a working dinner.
Asked whether he would raise concerns about human rights abuses and repression in Turkey, the premier's spokesman said: "No issue is ever off the table."
Mr Cameron will not be back in the UK in time for Prime Minister's Questions on Wednesday, with Liberal Democrat deputy Nick Clegg expected to fill in.