US President Donald Trump will visit Turkey later this year and according to the information thus far it will be around the same days the Russian S-400 anti-ballistic system will be on Turkish soil.

Details of the visit were agreed in a call on Tuesday between Ibrahim Kalin, a senior aide to Turkish President Recep Tayyip Erdogan and US National Security Advisor John Bolton.

Trump and Erdogan spoke to each other in a telephone call on Monday to discuss the S-400 deal, which the US has warned could allow Moscow to obtain critical data about its next-generation F-35 fighter jet programme in which Turkey is also a partner.