WASHINGTON  American diplomats are quietly urging the Kurdistan Regional Government in Iraq to take steps that would help ease the alarm over the Turkish troops amassed on Iraq's border.

Ankara, Washington, and Baghdad all rushed yesterday to deny an Associated Press dispatch that the Turks had begun an invasion of northern Iraq in pursuit of the Kurdistan Workers' Party, or PKK, a group listed as a terrorist organization by the State Department and blamed by the Turks for suicide blasts in their capital this year.

An Iraqi official who spoke on condition of anonymity explained the delicate American diplomacy as follows: "The Americans want the Kurds to make their lives easier. They need the Kurdish government to show they are willing to do something to tackle terrorism in the north. They are asking for them to be creative. They don't expect them to go after every cell, but maybe alert Turkey of a threat, act on intelligence, arrest some people, make an effort."

A State Department spokesman, Sean McCormack, said America's ambassador to Ankara met with the Turkish General Staff, who confirmed that the initial reports of the invasion were not accurate. Later, wire reports said the activity amounted to cross-border raids. Nonetheless, the director of the Turkish research program at the Washington Institute for Near East Policy, Soner Cagaptay, estimates that there are now 250,000 soldiers, most of whom have gathered in the last four weeks, massed at the Qandil mountain range on the border with northern Iraq. Those troops, according to Mr. Cagaptay, include heavy artillery and tanks, the most significant troop buildup by the Turks since they nearly invaded Syria in 1998 while accusing Damascus of harboring the PKK leader, Abdullah Ocalan. The Iraqi official yesterday said the figure of Turkish troops was closer to 100,000.

Should Turkey invade Iraqi Kurdistan, it would pit two American allies in the wider war against Islamic terror against each other. The troop buildup on the Iraqi border has worried the highest levels of the Bush administration, prompting Defense Secretary Gates over the weekend to warn the Turks not to go through with an invasion.

Yesterday Mr. McCormack reiterated that view from the podium at the State Department. After stating that America supports the Turks in their own battle against terrorism and that it considers the PKK a terrorist entity, Mr. McCormack said, "Turkey and Iraq are neighbors, that's not going to change. And we don't think it is in the interest of either state that there would be a military incursion into Iraq."

A representative of the Kurdistan Regional Government, Qubad Talabani, who is the son of Iraq's president, yesterday said he was worried about the rising tensions. "Of course we are concerned the tensions are rising between Turkey and the Iraqi Kurdistan region. We have constantly sought to deal with our issues through political and diplomatic channels," he said. "We feel the current build up of Turkish troops on our border is not helping either side reach a peaceful and political settlement." Mr. Talabani also said that no border posts on the Iraqi side had reported any Turkish incursions, and said the Turkish raids were confined to Turkish territory.

Mr. Cagaptay yesterday said that since 2002 the PKK has had an effective safe haven inside Iraqi Kurdistan, noting that 2002 when was when the Turks stopped most of their raids into northern Iraq against the PKK.

"Most of its members are in bases outside of Qandil and they have gone into Turkey, this is something I confirmed with Turkish military," he said. "When the PKK attacked Turkey from Iraq, the Turks would strike back, what is important about today's incursion, is that it tells us the relationship and that the restraint might be coming to an end." Mr. Cagaptay said that he predicted the Turks would be sending more soldiers into the area in the near future.

For America, the high tensions on Iraq's border with Turkey is a testament to how the current process headed by a former Air Force General, Joseph Ralston, to ease these tensions has not been working.