There are about 60,000 Turkish troops along the country's southern border, but the U.S. military is seeing no activity to suggest an imminent offensive against Kurdish rebels in northern Iraq, U.S. officials said.

As tensions mount between the U.S. and Turkey over a congressional resolution condemning the killings of Armenians a century ago as genocide, the Pentagon is both watching the border for troop movements, and planning for contingencies if Turkey restricts access to critical supply routes there.

A U.S. military official, speaking on condition of anonymity because of the sensitivity of the situation, said Friday that any offensive by Turkey into what has been a relatively peaceful area of northern Iraq would likely involve airstrikes and mortar fire.

But so far, the official said, there has been no evidence of Turkish soldiers massing along the border. The number of troops there isn't unusual, the official said.

U.S. military officials have said they believe they will get some type of warning if the Turks launch an incursion into Iraq against the rebel Kurdistan Workers' Party, or PKK. For years, the United States has routinely had military representatives with the Turkish armed forces.

The United States has consistently argued against a Turkish offensive, pushing instead for a broader diplomatic solution between Iraq and Turkey over the problem of the rebel PKK.

But of equal concern, however, is what impact the congressional resolution will have on U.S. military supply routes that have been used recently to move much-needed armored vehicles to troops in Iraq.

The House Foreign Affairs Committee this week passed a resolution labeling the World War I-era killings of up to 1.5 million Armenians by Ottoman Turks genocide. Turkey has argued that the toll has been inflated and the killings were the result of civil war and unrest.

Turkish authorities have not said whether further congressional action would prompt Turkey to shut down Incirlik air base in southern Turkey, a major hub for U.S. and coalition forces in Iraq and Afghanistan. Turkey's Mediterranean port of Iskenderun is also used to ferry goods to American troops.

And U.S. military officials said Friday that they have seen no indications of repercussions yet from the Turks.

But the Pentagon has dusted off contingency plans that would reroute supplies and arms if transportation through Turkey or across its airspace is restricted. There is more "focused planning" as a result of the congressional action, the official said.

One key impact could be on the delivery of mine-resistant ambush-protected vehicles (MRAPs) that the Pentagon has been trying to rush to Iraq. The vehicles give troops better protection against roadside bombs.

Officials are looking at plans to reroute those deliveries around Turkey if needed. Other supply routes — including those used during the ramp up to the invasion of Iraq in 2003 — could involve Kuwait and Jordan.

There also have been concerns that Turkey may cut off military contracts with the U.S.

Some of Turkey's largest recent purchases through the Pentagon's foreign military sales programs were $1.7 billion for F-16 aircraft; $1.6 billion (euro1.1 billion) to upgrade already owned F-16s, and to purchase four Airborne Early Warning Aircraft (AWACS) with an overall value of about $3 billion.

Turkey also bought torpedoes in an $80 million sale as part of a program to modernize its navy.

The U.S. each year budgets money under its foreign military financing program — essentially money given to Turkey to buy U.S. military equipment. Turkey received $34 million in budget year 2005 and $15 million in each of the next two years under that program.

The U.S. also budgeted $3 million in each of the last three fiscal years for Turkey in the international military education and training program, according to the State Department. The money was used to help Turkey transform its military to meet some European Union standards as well as provide other training and skills.