ISTANBUL (Reuters) - Turkey and Iraq already enjoy burgeoning trade and security cooperation, but Iraqi Kurdish leader Massoud Barzani's first visit to Ankara since the U.S. invasion in 2003 is a breakthrough for regional stability.
Turkey's political and military establishment has long reviled Barzani, president of Iraq's Kurdish autonomous government, as a sympathizer with Turkey's Kurdish rebels and a supporter of Kurdish independence.
Barzani, who arrived in Ankara on Wednesday, is expected to discuss cooperation with Turkey in its fight against Kurdistan Workers' Party (PKK) guerrillas who attack Turkish forces from bases in northern Iraq, and his visit will also help break down barriers between the Turkish state and its own ethnic minority.
Henri Barkey of the Carnegie Institute for International Peace said Barzani's landmark visit, unimaginable only a few years ago, showed how dramatically Turkish policy toward Iraqi Kurds and Turkish strategy on Iraq had changed.
Tension between Turks and Kurds has made for instability in southeast Turkey and the border region for years, but the two governments have recently given higher priority to cooperation.
"Someone who was only referred to as a tribal leader and unwelcome in Turkey is now being received with dignity," Barkey said. "Turkey understands that Iraqi Kurds are its most natural allies, dependent on Ankara for trade and diplomatic support."
Until recently Turkey tried to isolate Iraqi Kurds, worried that their autonomy, enshrined in the Iraqi constitution, would stoke separatism among its own estimated 15 million Kurds.
Prime Minister Tayyip Erdogan's government now believes Turkey can wield greater influence in Iraq -- and balance Iranian clout in Baghdad -- by boosting relations with the Kurds before the U.S. troop withdrawal in 2011, analysts said.
"Mutual trust between Kurdistan and Turkey is key to stability in our region. One reason Kurds have drawn closer to Turkey is the U.S. decision to withdraw from Iraq," said Sahin Alpay, a professor at Bahcesehir University in Istanbul.
Iraq faces a deepening power vacuum nearly three months after an election that has failed to produce a government. Kurds are seen as key players in the formation of a new government.
Barzani's visit coincides with a jump in violence by the PKK, and a Turkish foreign ministry official said Turkey expects him to "send a strong message against terrorism."
"It's time for solidarity against terrorism. Barzani shares our position. He is coming within this framework," Turkish Foreign Minister Ahmet Davutoglu told reporters.
The two sides will discuss security matters, trade and energy links and the general election, said Safeen Dizayee, a minister in the Kurdistan Regional Government.
Iraqi Kurdistan has awarded Turkish companies lucrative construction and energy contracts, and trade reached $9 billion last year, according to the Turkish Foreign Ministry.
Istanbul-based conglomerates Cukurova and Dogan Holding are developing oil in the region, which has reserves of up to 40 billion barrels. Kurdistan wants to build a $1 billion oil pipeline to Ceyhan on Turkey's Mediterranean coast.
"Iraqi Kurds have put to rest Turkey's concerns about whether Iraqi unity will be protected," said Dogu Ergil, political science professor at Ankara University. "Of all their neighbors, Kurds trust and need Turkey the most in the region, and trade ties have solidifed that."
Resolving disputes with neighbors is a cornerstone of Ankara's foreign policy as it seeks to become a regional power.
Erdogan has expanded Kurdish political and cultural rights in an effort to end the 25-year conflict with the PKK. But progress in the so-called Kurdish opening has slowed this year.
Turkey, the United States and the European Union all label the PKK a terrorist organization.
Additional reporting by Tulay Karadeniz in Ankara; editing by Tim Pearce