Russian Prime Minister Vladimir Putin is to visit Ankara Thursday for talks expected to focus on energy cooperation amid a growing Turkish role in projects to carry gas and oil to Europe.
"Cooperation in the field of energy will be a primary issue on the agenda," an aide to Turkish Prime Minister Recep Tayyip Erdogan said.
Situated between Europe and the vast oil and gas fields of the Caspian Sea and the Middle East, Turkey has emerged as a hub for pipelines to supply the energy-hungry West.
Last month, Ankara hosted the signing of a long-delayed accord to build the Nabucco pipeline to carry Caspian gas via Turkey to Bulgaria, Romania, Hungary and Austria, bypassing Russia.
The project, planned to become operational in 2014, aims to reduce European reliance on Russia and avoid a repetition of cut-offs that disrupted winter supplies and sparked accusations Moscow was using gas as a political weapon.
Turkey however has been careful not to antagonize Russia - its top trading partner and main gas supplier - and Erdogan has insisted that Russia should also join the countries that would provide gas for Nabucco.
"This is a long-term proposal," Erdogan's aide said. "Russia's participation in the project would not harm the aim of diversifying energy supply."
In direct competition with Nabucco, Russia is pushing for its own project to pump gas to Europe - South Stream - and might seek Ankara's support to have the pipe pass through Turkish territorial waters in the Black Sea rather than Ukrainian waters, according to Turkish media.
Russia and Turkey aren't outright rivals in the energy field and their ties instead resemble "that game in which children try to pull each other to their side across a line," columnist Semih Idiz wrote in the Milliyet daily Monday.
Turkey is already directly linked to Russia through the Blue Stream gas pipeline, which runs under the Black Sea.
Hoping to attract Russian and Kazakh oil, Ankara is also promoting a pipeline from its Black Sea port of Samsun to Ceyhan on the Mediterranean coast, which already serves as a terminal in conduits pumping oil from Azerbaijan and Iraq.
Putin's energy agenda in Ankara is likely to include also a long-delayed project to build Turkey's first nuclear power plant.
Russia's state firm Atomstroyexport was the only bidder in an auction in January, but the Turkish government is yet to decide whether to award it the project amid misgivings over the financial terms the company offered.
Erdogan's aide said the two prime ministers would also discuss regional affairs in the Caucasus.
Russia has been mediating talks between Armenia and Azerbaijan over the Nagorny Karabakh dispute, the settlement of which is crucial for speeding up Ankara's efforts to reconcile and establish diplomatic ties with Yerevan.
Another prominent issue is Georgia, whose North Atlantic Treaty Organization membership Turkey supports, despite fierce Russian opposition.
Russia's military intervention in the former Soviet republic last year briefly strained relations with Turkey, which has close economic and political ties with Georgia, its northeastern neighbour.
Turkey sought to tread carefully and proposed a regional platform for stability and cooperation in the Caucasus that will bring together the two foes as well as Azerbaijan, Armenia and itself.
Despite sometimes shaky political ties, economic exchange between the two countries has boomed since the fall of Communism: in 2008, their trade volume hit $37.8 billion, making Russia Turkey's number one trading partner.
Russia supplies about 60% of Turkey's gas imports, and more than a million Russian holiday-makers boost Turkey's vital tourism sector each year.