Johnson, who is partly of Turkish ancestry, began his trip with a visit to a camp for Syrian refugees in the southeast, before heading to Ankara for political talks.
The flamboyant former London mayor may find aspects of his visit awkward after he penned the winning entry in a competition on offensive poetry about President Recep Tayyip Erdogan, published by the conservative British magazine The Spectator.
The trip is the highest-level visit to Turkey by a British official since the failed coup on July 15 in which a rogue military faction tried to overthrow the Turkish strongman.
"shoulder-to-shoulder with Ankara" and said Turkey had a "vital role to play" in the global arena.
He indicated Britain would still support Turkey's bid to join the EU despite the British vote to exit the bloc.
"We may be leaving the European Union but we are not leaving Europe. And Britain... Will help Turkey in any way," he said at a news conference with EU Affairs Minister Omer Celik.
Johnson, one of the most prominent public faces of the campaign for Britain to leave the European Union, previously made a strong case for Turkish membership of the bloc.
David Cameron, who resigned as British prime minister after the Brexit vote, also said during the campaign that Turkish EU membership was not "remotely on the cards" and may not happen until the year 3000, further angering Ankara.
Before the Brexit vote, Britain was always seen as one of the strongest supporters of Ankara's bid for EU membership.
Extolling trade between the countries, Johnson boasted that he was the proud "possessor" of a "beautiful" Turkish washing machine.
Turkey, a fierce opponent of President Bashar al-Assad, is hosting nearly three million Syrian refugees who have fled the war, and has been pressing for a safe zone on the Syrian side of the border to house refugees.
Disclaimer: No Business Standard Journalist was involved in creation of this content
