Russian President Vladimir Putin said he will talk to US counterpart Donald Trump on the telephone on Tuesday after an unannounced meeting with Syrian leader Bashar al-Assad in Sochi.

"On the basis of our meeting today, I will hold consultations with the leaders of the countries that I already spoke about. There is already a planned talk with the Emir of Qatar today and tomorrow (another one) with the president of the United States Donald Trump," Putin told Assad on Monday.

A transcript of the conversation was published on the Kremlin website on Tuesday.