Prime Minister Recep Tayyip Erdogan has harshly criticised the US and Iraq for inaction against the PKK and faces mounting calls at home for a cross-border military operation into neighbouring northern Iraq to crack down on the PKK.

"We have many actions in front of us that we have been working on to counter the PKK," Ralston said after lengthy talks with Turkish counterpart Edip Baser and Foreign Minister Abdullah Gul.

"We remain very focussed on this effort with a lot of initiatives and I'm hopeful that, if we can have some patience on the part of Turkish people, we will be successful in our task," he said.

Ralston expressed hope that Massud Barzani, a key US ally and president of the Kurdish autonomous region in northern Iraq, whose ties with Ankara have notably deteriorated in recent months, would also help against the PKK.

"I believe that I can convince him that the PKK is a threat to the stability of northern Iraq as well as a threat to the Turkish people and I have solicited his help in closing down and countering the PKK," Ralston said.

Baser said "certain progress" was achieved in the talks with "certain steps that will take us forward... and other steps that we still need to work on."

Both officials declined to elaborate on what measures were planned.

Earlier this month, Erdogan said Ralston's appointment in August had produced no results and asked whether it was "a tactic" to distract Turkey.

He said PKK offices in Iraq remained open despite an announcement by Baghdad in September that they would be closed and said that some PKK militants infiltrating Turkey carried US-made weapons and bombs.

Ankara says northern Iraq has become a training ground for the PKK, where the group enjoys unrestricted movement and is easily able to obtain weapons and explosives for attacks on Turkish territory.

The US argues that it is swamped by violence in other parts of Iraq and says it is working to curb the PKK through non-military means such as cutting off its financial resources.