FACTBOX: Obama visit bolsters U.S.-Turkey ties

(Reuters) - President Barack Obama's will seek on Monday to shore up ties with Turkey, a Muslim country with growing clout whose help Washington needs to solve confrontations and conflicts from Iran to Afghanistan.

Here are some topics expected to be discussed during Obama's visit, his first to a Muslim country since elected president.

IRAQ

U.S.-Turkish ties suffered badly in 2003 when Ankara opposed the Iraq invasion, but the two allies share vital interests in the stability of Iraq. Turkey is a logistical hub for U.S. forces set up to withdraw from Iraq, and Turkey's Incirlik air force base is expected to play a key role. Prime Minister Tayyip Erdogan has said Turkey would allow U.S. troops to use its bases and ports to withdraw troops from Iraq.

Until recently, Turkish officials had been angered that Washington was not putting enough pressure on Iraqi officials to crack down on separatist rebels of the Kurdistan Workers' Party (PKK), who have bases in northern Iraq. PKK attacks have been a strain to Iraqi-Turkish ties, but in January Turkey, Iraq and the United States agreed to set up a joint command center in northern Iraq to gather intelligence to fight PKK rebels.

With U.S. intelligence, the Turkish military has carried out air strikes and shelled PKK areas in northern Iraq.

IRAN

With U.S.-Iranian relations in flux after Obama's offer of better ties last month drew an Iranian demand for U.S. policy changes, Washington values Turkey's input on its neighbor. Iran and Turkey are close historically and culturally, and Turkey has said it would consider serving as mediator between Tehran and Washington.

Last month, Turkish President Abdullah Gul made a visit to Iran, where he met President Mahmoud Ahmadinejad and Supreme Leader Ayatollah Ali Khamenei, Iran's most powerful authority.

Secretary of State Hillary Clinton has said Washington will seek Turkey's help for Obama's plan to engage Iran.

AFGHANISTAN

Turkey is also a major transit route for U.S. troops and equipment destined for Afghanistan, where U.S. and other NATO forces are fighting a Taliban insurgency. Obama wants a regional approach to Afghanistan, and Washington could use Turkey to convince its neighbors to allow their territory to become supply routes to Afghanistan.

Ankara can also play a key role in Obama's strategy to get Afghanistan and Pakistan to work together in fighting al Qaeda and Taliban militants in their borders. Turkey has hosted three high-level talks between Pakistan and Afghanistan. Turkey has some 800 troops in Afghanistan, in and around Kabul, as part of NATO's International Security Assistance Force (ISAF). It is reluctant to have combat troops in Afghanistan, but wants to play a bigger political role in solving the conflict.

MIDDLE EAST

Obama will find Turkey an invaluable ally as it tries to reach out to Damascus and as it engages in Israeli-Palestinian peacemaking. The Islamist-rooted AK Party, which swept to power in 2002, has cemented ties with the Middle East, rediscovering a region which it was an integral part of under the Ottoman Turks.

Turkey hosted indirect peace talks between Israel and Syria. It also has good relations with Hamas, the Palestinian militant group, and helped broker a ceasefire after Israel's Gaza offensive. Turkey has tried to bridge differences among Palestinians.

ARMENIA

Turkey and long-time foe Armenia are engaged in diplomatic contacts to restore ties after a century of hostility, but the killings of Armenians by Ottoman Turks in 1915 remains a thorny issue and could affect U.S.-Turkish relations.

Obama pledged during his election campaign to call the killing of Armenians "genocide." Ankara accepts that many Armenians were killed during World War One, but strongly denies that up to 1.5 million died as a result of genocide. The issue has poisoned bilateral ties before, but officials in Ankara and Washington have played down any potential fallout ahead of Obama's visit and instead want to focus on areas of cooperation.

Resolving the Turkey-Armenia dispute is important because it is linked to Nagorno-Karabakh, a mountainous enclave claimed both by Azerbaijan and Armenia. Nagorno-Karabakh is one of the most serious sources of tension in the volatile, oil-rich Caucasus.

OIL SECURITY

With Russia flexing its muscles in the Caucasus, the United States is keen to reinforce Turkey's ambitions of becoming a transit route of Central Asian oil for Europe. Washington, along with the European Union, back the ambitious Nabucco project that would take Azeri oil to Europe via Georgia and Turkey.

Sources: Reuters/countrystudies.us/turkey/

(Writing by David Cutler, London Editorial Reference Unit and Ibon Villelabeitia in Ankara)