A readout from Turkey's Defence Ministry of a phone call between the two ministers said Akar told Shoigu that it was very important for the grain deal to continue and added that it should be implemented separately from the conflict in Ukraine.

What would Turkey be willing to do I wonder

They're a huge trade country. Turkey has a lot of vested interest in seeing all their trade routes and partners stable, so they have incentive to pressure Russia to allow grain to flow.

Turkey should re-evaluate the deal that lets ruzzian ships enter or leave the black sea. If ruzzia refuses to uphold its deals, no one should uphold their deals with ruzzia!

What leverage do they have over Russia?

Transit of the Straits, ever again.

But do they have right to deny the transit from international law perspective?

Fully deny? No.

But they can insist on daylight transit, with one ship at a time, can deny warships completely unless they're returning to base, and can impose an inspection regime. And as Russia has proven over the last month, rigorous inspection regimes of large ships can result in a 195-ship tailback.

I see, thanks.