ON Thursday afternoon, Russian President Vladimir Putin rang the Turkish President, Recep Tayyip Erdogan, and told him what Russia's precise demands were for a peace deal with Ukraine.

Within half an hour of the ending of the phone call, BBC interviewed Mr Erdogan's leading adviser and spokesman, Ibrahim Kalin.

Mr Kalin was part of the small group of officials who had listened in on the call.

The Russian demands fall into two categories.

The first four demands are, according to Mr Kalin, not too difficult for Ukraine to meet.

Chief among them is an acceptance by Ukraine that it should be neutral and should not apply to join Nato. Ukraine's President Volodymyr Zelenskyy has already conceded this.

There are other demands in this category which mostly seem to be face-saving elements for the Russian side.

Ukraine would have to undergo a disarmament process to ensure it wasn't a threat to Russia. There would have to be protection for the Russian language in Ukraine.

And there is something called de-Nazification.

This is deeply offensive to Mr Zelenskyy, who is himself Jewish and some of whose relatives died in the Holocaust, but the Turkish side believes it will be easy enough for Mr Zelenskyy to accept.

Perhaps it will be enough for Ukraine to condemn all forms of neo-Nazism and promise to clamp down on them.

Mr Kalin was much less specific about these issues, saying simply that they involved the status of Donbas, in eastern Ukraine, parts of which have already broken away from Ukraine and stressed their Russianness, and the status of Crimea.

Although Mr Kalin didn't go into detail, the assumption is that Russia will demand that the Ukrainian government should give up territory in eastern Ukraine. That will be deeply contentious.

The other assumption is that Russia will demand that Ukraine should formally accept that Crimea, which Russia illegally annexed in 2014, does indeed now belong to Russia. If this is the case, it will be a bitter pill for Ukraine to swallow.