A letter from US President Donald Trump to Turkish President Tayyip Erdogan will be included in textbooks on international diplomacy or international relations, said Russian Foreign Ministry spokeswoman Maria Zakharova.

Trump sent a letter to Erdogan asking him not to play the fool and not to let the whole world down with a military operation in Syria,  RIA Novosti reported.

“This style of the epistolary genre will be included in textbooks on ... international diplomacy or international relations, but this is the style of the United States of America, the style of the political system, the style of relations with partners,” he said.