ARBIL, NORTHERN IRAQ - US Special Forces have attached themselves to Kurdish military units to call in air strikes on Iraqi army positions when the Kurds advance at the start of the invasion of Iraq by US and Britain.

Gen Azad Miran, Chief of Military Operations for the 62,000-strong army of the Kurdistan Democratic Party, said yesterday that Kurdish forces would rely on specialised American soldiers accompanying them to call in tactical air support "because we do not have the equipment to do that."

More US Special Forces are expected to arrive shortly in northern Iraq to reinforce some 130 already here. They will accompany Pesh Merga (Kurdish soldiers) units as they fight their way towards the key northern Iraqi cities of Kirkuk and Mosul, but they will not enter them because of fear that this would lead to a Turkish invasion.

The US strategy has shifted towards greater reliance on the lightly armed but experienced Kurdish forces in order to bolster the northern front against the Iraqi army. The US hopes of sending a land army through Turkey to invade northern Iraq were dashed when the Turkish parliament refused to allow the use of Turkish bases by the US.

Asked if each Pesh Merga unit would have US soldiers with them a top Kurdish military official said: "That is what is happening."

The US is now playing a crucial but secretive role in northern Iraq, using its highly-trained Special Forces much as they were used against the Taleban in Afghanistan, to support the lightly armed Kurdish infantry with massive US air power.

The Kurdish assault will be coordinated with the US. Masrur Barzani, the chief of KDP intelligence, said yesterday: "It would not be in our interests to take decisions without coordinating with our friends."

"We have a strategy to control the Kurdish areas under the rule of the Iraqi regime," said Gen Miran in an interview with the Independent. "We are not talking about the cities of Kirkuk and Mosul, but the countryside is where we will operate."

Massoud Barzani, the head of the KDP, said, however, that he hoped a Kurd would raise the flag of victory over Kirkuk.

The Iraqi army's northern front is held by the 5th and 1st Corps backed by two elite Republican Guard divisions, though these are beginning to send their armoured units south closer to Baghdad. Kurdish commanders stress that they cannot move without American air cover, under the control of forward air controllers with the Pesh Merga, which they expect to knock out Iraqi artillery and tanks.

The US attack on northern Iraq is to be supplemented by its airborne brigades. Experienced Kurdish officers say it is likely that the US will strike from eastern Jordan, taking Iraqi army positions on the northern Euphrates such as Haditha which has a good airport. They believe that the cities of Mosul and Kirkuk are not ultimately defensible and Saddam Hussein does not trust the regular army divisions stationed there to fight.

Iraq's much feared security forces are reported to have taken their confidential papers to Baghdad for safe keeping. Arab settlers in formerly Kurdish villages are preparing to leave, even dismantling heavy equipment like water pumps before they move south.

Military preparations within the Kurdish safe haven in northern Iraq, long defended by US and British airpower, are increasingly visible and there are signs that war is very close. In the mountain-top town of Salahudin yesterday some 600 soldiers with Kalashnikovs and rockets, who had just completed seven months, training, were marching down the main street. In the front line Pesh Merga are assembling in ever greater numbers.

The Kurds and the US are anxious not to offend Turkey which has said that it will launch its own invasion rather than see the Kurds occupy Kirkuk or Mosul. However Massoud Barzani says he is absolutely determined to see the 300,000 Kurds return to areas from which they were ethnically cleansed by the government in Baghdad over the last thirty years.

Kurdish leaders, who will be part of an Iraqi opposition delegation, are expected to have a critical tripartite two-day meeting with Turkish and US officials starting today in Ankara. The Kurds will try to allay Turkish fears about Kurds declaring independence, taking the northern cities or refusing to recognise the rights of the Turkomans in Kirkuk.

The US, originally willing to countenance a Turkish invasion of northern Iraq in return for American use of Turkish bases, has reversed its position. It is now pressing the Turks not to attack. If they do, then KDP officials have said their army will fight them. A Turkish invasion would also lead to the KDP forces no longer being able to support the US war effort. Massoud Barzani said: "If the Turks come in there will be a war, it will be major war."