Recep Tayyip Erdogan, Turkey’s prime minister, is due to meet George W. Bush in Washington on Monday amid signs that a diplomatic and military crisis over PKK Kurdish separatist attacks across the Turkish-Iraqi ­border has slightly eased.

As Mr Erdogan was en route to the US, the PKK released eight Turkish soldiers it had captured two weeks ago in an incident that led to overt threats by Turkey to send its army into northern Iraq to crush the rebels’ bases there.