ANKARA, Feb 3 (AFP) - US Secretary of State Condoleezza Rice arrives here at the weekend facing the tough task of allaying Turkish fears that an independent Kurdish state -- Ankara's long-standing bete noire -- is taking shape in Iraq as Washington turns a blind eye.

Ties between the two NATO allies have failed to fully recover since hitting an all-time low prior to the US-led invasion of Iraq in March 2003, when Turkey stunned Washington by denying it access to its territory to mount an attack on Iraq from the north.

Analysts fear new tensions may be now looming, with Ankara increasingly frustrated over what it sees as US reluctance to rein in Kurdish moves to take control of the oil-rich city of Kirkuk in northern Iraq as part of a suspected plot to break away from Baghdad.

"The issue of northern Iraq is of vital importance for Turkey. The Americans say they understand Turkey but when it comes to action on the ground there is no reason for trust," said Bahadir Koc from the Ankara-based ASAM think-tank.

Independence-minded moves in northern Iraq, Ankara fears, will embolden separatism across the border in southeastern Turkey, where a Kurdish rebellion has already claimed some 37,000 lives.

Turkish suspicions were reinforced when large numbers of Kurds said to have been expelled from Kirkuk under Saddam Hussein were allowed to settle and vote in the city in last week's elections, despite protests by rival ethnic groups that many of them have no bonds with Kirkuk.

As the Kurds braced for large political gains, Turkish Prime Minister Recep Tayyip Erdogan slammed the United States this week, charging that "forces who say they came to the region to bring democracy have preferred to remain indifferent to anti-democratic ambitions."

He warned that "any step taken without consideration for Turkey's rights will yield no result other than fanning the fire in the region."

Foreign Minister Abdullah Gul said Ankara could take action if ethnic unrest erupts in Kirkuk, which is also home to a large community of Turkish-speaking Turkmens.

Turkish frustration had already been running high over US reluctance to move against some 5,000 Turkish Kurd rebels who had found refuge in the mountains of northern Iraq prior to the war and last summer ended a five-year unilateral ceasefire with Ankara.

Washington has promised to act against the rebels -- members of the Kurdistan Workers' Party (PKK) which it considers a terrorist group -- but has so far failed to take military measures, arguing that its troops are swamped dealing with violence in other parts of Iraq.

"Turkish-US relations used to be called a 'strategic alliance.' To talk about this today is tragicomic," Koc said.

Still, the fact that Rice has included Turkey as a port of call on her first foreign tour as secretary of state is important, he said.

"This shows they recognize they have problems with Turkey and want to listen to it," he added.

Beril Dedeoglu, an expert on international relations at Istanbul's Galatasaray University, said Ankara's harsh rhetoric was rather aimed at pleasing its public, which is overwhelmingly against the US presence in Iraq.

"Recent statements like those by Erdogan do not serve Turkish interests," she said. "One has to be realistic."

Ties with the United States continue to be "strategic," she argued, pointing to Turkey's role as a friend in a troubled region, also bordering Syria and Iran, and Ankara's close ties with Israel.

"Rice will likely try to convince Turkey on the PKK issue and give a guarantee that independence is not be possible for northern Iraq," she said.

Following talks in Ankara this week, US undersecretary of defense Douglas Feith pledged that bilateral ties remained strong and confirmed that Washington was seeking to use a key base in southern Turkey as a logistical cargo hub for US forces operating in the region.

Rice is scheduled to meet with Gul, Erdogan and President Ahmet Necdet Sezer on Saturday and Sunday.