Russian President Vladimir Putin visits Turkey today with trade and energy issues set high on the agenda.

Russia is Turkey’s main energy supplier and Ankara is Moscow’s second biggest trade partner after Germany.

However deep differences over Syria and Crimea could blot proceedings and delay an agreed revision in gas prices.

Turkish President Recep Tayyip Erdogan has strongly criticised Russia’s backing for Syrian President Bashar al-Assad. And Turkey has strong links with the Muslim Tatar population in Crimea, which Russia annexed from Ukraine in March.