Factbox-Partners or rivals? Russia and Turkey navigate awkward alliance

ANKARA (Reuters) - Turkey's defence purchases from Russia have alarmed Ankara's NATO partners but the two countries remain rivals in wars from the Middle East to the Caucasus, highlighting the faultlines running through their awkward alliance.

Turkey has bought Russian missile defence systems and could buy more equipment from Moscow. It imports Russian gas, hosts millions of Russian tourists and says membership of the Western NATO alliance is no barrier to building ties with Moscow.

But it has also deployed troops in north Syria to push back Russian-backed Syrian government forces, and the two countries backed rival sides in the wars in Libya and Nagorno-Karabakh.

Ahead of Wednesday's summit between Vladimir Putin and Tayyip Erdogan, here is a summary of the ties that bind and the rifts that divide Moscow and Ankara.

REGIONAL RIVALS

- In Syria, Turkey backs fighters who once appeared close to toppling President Bashar al-Assad, until Russian intervention shored up the Syrian leader and helped drive the insurgents back to a small pocket of northwest Syria on the Turkish border.

In February 2020, when an air strike killed at least 34 Turkish soldiers, Turkey poured reinforcements into the northwestern Idlib region to stall advances by Russian-backed Syrian government forces which had displaced 1 million people.

In the build-up to this week's summit, Turkey-backed rebel fighters say Russia has escalated air strikes.

They say Turkey has again sent more forces to the region, although officials in Ankara say they have been mainly troop rotations, rather than reinforcements.

- In Libya, Turkey's military intervention turned back an assault on the internationally recognised government in Tripoli by the eastern-based forces of Khalifa Haftar.

United Nations experts say the Russian Wagner Group has sent fighters to support Haftar's forces, while Turkey has sent Syrian fighters to back the Tripoli government.

Under a ceasefire reached last October, foreign fighters were supposed to have left by January, a deadline all sides appear to have ignored.

- Turkey supported Azerbaijan's military assault to drive ethnic Armenian forces out of much of the mountainous Nagorno-Karabakh enclave in the south Caucasus last November.

Moscow has a defence pact with Armenia and views the region on its southern flank, made up of former Soviet republics, as part of its own backyard. Putin brokered a peace deal to stave off a total defeat of ethnic Armenian forces.

- Turkey has not recognised Russia's annexation of Crimea and says it is important to maintain Ukraine's sovereignty - a message which has irked Moscow and which Erdogan repeated at the United Nations last week.

When Erdogan pledged in April to support Kyiv amid a build-up of Russian forces along the Ukrainian border, Russia warned Turkey not to fuel "militaristic sentiment".

PARTNERSHIP

- Two years ago Turkey took delivery of Russian S-400 missile defence batteries, eventually triggering U.S. sanctions on Ankara's defence industries.

Despite warnings from Washington that further Russian arms purchases would bring additional U.S. sanctions, Erdogan said no country could dictate Ankara's acquisitions and suggested it would buy a second batch of S-400s.

- Russia has so far this year accounted for around half of gas imports to Turkey, which is heavily import-reliant for its energy needs, after slipping to one third last year when a main pipeline was under repair for four months.

A recovery in consumption from last year's pandemic-induced dip also boosted volumes of Russian gas.

- Seven million Russian tourists visited Turkey in 2019, the largest number from any country, before the pandemic drastically cut foreign travel. Tourism remains a significant source of hard currency for the Turkish economy.

- Russian nuclear conglomerate Rosatom is building a nuclear plant at Akkuyu in southern Turkey, which Putin has said will start working in 2023.

(Reporting by Dominic Evans and Can Sezer; Editing by Gareth Jones)