Russian President Vladimir Putin and Turkey's Recep Tayyip Erdogan vowed Wednesday to improve cooperation as they launched the construction of a new reactor at Turkey's first nuclear power plant.

The two leaders each pressed a button on their office desks in Moscow and Ankara in a video link ceremony unveiling the third phase of Akkuyu station's construction project.

Russia's Rosatom state nuclear energy firm began building the first of four planned reactors on Turkey's south coast in 2018.

Erdogan hopes to put the plant online by the time Turkey celebrates its centenary as a post-Ottoman republic in 2023.

Putin said he expected the project to "improve the Russian-Turkish partnership in all its facets, helping strengthen friendship and mutual understanding between our countries' peoples".

Erdogan echoed similar thoughts.

"The close dialogue that we established with my esteemed friend (Putin) is playing a key role not only in bilateral relations but also in preserving regional peace and stability," Erdogan said.

Russian news reports estimate the cost of the entire project at around $20 billion (17 billion euros).

Turkey is heavily reliant on oil and natural gas imports -- including from Russia.

Erdogan said he expected the plant to supply 10 percent of Turkey's electricity needs when completed.