Stephen J. Hadley embarked on his first solo mission overseas since becoming President Bush's national security adviser, arriving here Friday to shore up relations with a key ally before heading to Afghanistan and Pakistan to view the front line in the struggle against terrorism.

With volatile situations brewing all around this region, Hadley chose to stop first in Turkey to consult with the United States' closest partner in the Muslim world on such topics as Iraq, Syria and Iran. At the same time, he promised to "do more" to combat Kurdish guerrillas targeting Turkey from northern Iraq, a top priority of the Turkish government after a recent series of bombings.

"PKK is a terrorist organization," Hadley said, referring to the Kurdistan Workers' Party. "We condemn its activities. We understand that its activities in northern Iraq affect Turkey and cost Turkish lives. And the coalition and the Iraqi transitional government and Turkey need to work together to do more against this threat. We need to do more in northern Iraq."

Hadley offered no details about what more could be done in Iraq. But the Turks have given the United States intelligence reports detailing alleged sources of financial and other support for Kurdish separatists in the United States, Europe and elsewhere. The Turks have sought action against PKK satellite television broadcasts operating from Denmark and New Zealand.

Hadley suggested the United States would step up efforts to strangle outside aid. "We also need to do more to disrupt fundraising and other activities elsewhere that support the PKK," he said after meeting with Prime Minister Recep Tayyip Erdogan.

Hadley's five-day trip amounts to an international debut of sorts. A quiet, unassuming lawyer, he served as deputy national security adviser in Bush's first term and moved up to the top post after Condoleezza Rice became secretary of state in January. But he has assumed a low profile in his first eight months on the job, allowing her to become the unquestioned spokeswoman for the United States abroad.

Although he has been a central figure in Bush's campaign against terrorism for four years, Hadley has never been to Afghanistan. He will travel there to meet with President Hamid Karzai and will make his first visit to Pakistan in three years to see that country's president, Gen. Pervez Musharraf.

The trip will put Hadley in the middle of tension between Afghanistan and Pakistan over the flow of guerrillas back and forth across their common border. Karzai said this week that the United States should shift its military strategy in Afghanistan away from airstrikes and major operations and focus instead on shutting down the flow of foreign support for remnants of the Taliban and al Qaeda that are still fighting, a reference to longstanding complaints that Pakistan serves as a haven for guerrillas.

Hadley decided to make Turkey his first overseas destination in the new job in part because it was the first country he visited as assistant secretary of defense under President George H.W. Bush. But his visit also reflects a flurry of high-level U.S. attention to Turkey more than two years after relations soured over the country's refusal to allow U.S. forces to invade Iraq from its territory.

Rice visited Turkey in February. After Hadley leaves, the newly sworn-in undersecretary of state for public diplomacy, Karen Hughes, will arrive as part of a regional tour to improve the U.S. image abroad, to be followed soon after by the undersecretary of state for arms control, Robert Joseph.

The Bush administration is eager for Turkey to reinforce U.S. diplomacy in the Middle East, particularly in Syria if a U.N. investigation concludes that the government there was responsible for the assassination of former Lebanese prime minister Rafiq Hariri. The administration also looks to Turkey for help in promoting peace between the Israelis and Palestinians.

But Turkey often prefers to look west to Europe, where it sees its economic and political future. After years of debate, the European Union is to begin talks Oct. 3 to consider Turkish membership. Hadley restated U.S. support for that: "Our vision for Europe is a Europe whole, free and at peace, in which Turkey is a full and valued member."

Stephen J. Hadley promised to "do more" against Kurdish attacks.