"There are 25 major agreements on the table here. They range from removing tourist visas completely for citizens of both countries travelling between them [and] more work on building gas and oil pipelines crossing each others territory."

But she said the most significant agreement to be signed is a nearly $1bn deal for the construction of Turkey's first nuclear power station on the Mediterranean coast.

"It's a hugely controversial project, it's been years in negotiation and today that deal is meant to be inked," she said.

Russia has long looked to build Turkey's first nuclear power plant. But last year, a Turkish court scrapped a tender won by a Russian-led consortium.

More active role

Medvedev's visit to Turkey followed a trip to Syria, where he called for a more active US role in the Middle East peace process, saying the situation in the region was "very bad" and risked worsening further.

"In essence, the Middle East peace process has deteriorated," Medvedev said, speaking alongside Bashar al-Assad, his Syrian counterpart, after two days of talks on the first visit to Damascus by a Russian head of state.

"The situation is very, very bad. It's time to do something. I agree with President Assad, the American side could take a more active position."

Medvedev's visit came against the backdrop of a nearly 18-month-old suspension of Turkish-led peace efforts between Israel and Syria.

There has been a mounting war of words between the two foes over Israeli accusations that Syria has been arming Lebanon's Hezbollah with Scud missiles.

Fraught with troubles

Medvedev's trip also came as renewed US-brokered peace talks between Israel and the Palestinians ran into difficulties just days after their launch over Israeli settlement expansion in annexed East Jerusalem.

"A further heating up of the situation in the Middle East is fraught with an explosion and a catastrophe," he said.

Russia is part of the so-called international Quartet working for a Middle East settlement alongside the European Union, the US and the UN.

"There is not enough desire" on all sides to find a solution, Medvedev said. "This desire needs to be stimulated."

He said that was a role that Moscow could and would take upon itself.