By , ISTANBUL (Reuters) - President Tayyip Erdogan said on Friday U.S. sanctions over Turkey’s purchase of Russian S-400 missiles would be disrespectful to a NATO ally, after sources said Washington was poised to take the step likely to further strain relations.The report of imminent U.S. sanctions targeting Turkey’s defence industry over missiles comes as EU leaders at a summit discussed separate sanctions against Turkish officials over gas exploration in disputed parts of the Mediterranean.Both developments -- examples of Erdogan’s long-strained relations with Western allies -- have...…By , ISTANBUL (Reuters) - President Tayyip Erdogan said on Friday U.S. sanctions over Turkey’s purchase of Russian S-400 missiles would be disrespectful to a NATO ally, after sources said Washington was poised to take the step likely to further strain relations.The report of imminent U.S. sanctions targeting Turkey’s defence industry over missiles comes as EU leaders at a summit discussed separate sanctions against Turkish officials over gas exploration in disputed parts of the Mediterranean.Both developments -- examples of Erdogan’s long-strained relations with Western allies -- have...WW…