JERUSALEM: Turkey has canceled an annual multinational air force drill including the US and NATO because it opposed Israeli participation, the Israeli military said Sunday, in a sign of further deterioration in relations between the two countries.

Turkey had long been Israel’s closest ally in the Muslim world. But ties have suffered since Israel’s winter war against Hamas in the Gaza Strip, which killed hundreds of civilians.

A brief statement posted on the Turkish military’s website said the annual Anatolia Eagle drill would take place Oct. 10-23, but that international participation had been canceled after “international negotiations conducted by the Turkish Foreign Ministry.” The statement did not elaborate.

Turkish military officials were not available for comment, and a government spokesman said he had nothing to add to the military’s statement.

The Israeli military said in a statement that the drill was delayed indefinitely “because of Turkey’s decision to change the list of participating countries, thus excluding Israel.” The exercise was to have been the sixth annual maneuver of its kind. The military said it was also to have included US, Italian and NATO forces.

Israeli defense officials said Ankara canceled the drill after the US pulled out over the Turkish decision to exclude Israel.

Deputy Israeli Foreign Minister Danny Ayalon appeared to be trying to keep the heat down, calling Turkey a “very important strategic anchor in the Mideast.” “Certainly its ties with Israel serve the entire region,” Ayalon told Israel Radio, adding that “all of us want a tolerant Turkey that is part of Western civilization, and certainly an antithesis to the Iranian model.”

Israel and Turkey have wide-ranging military, economic and strategic ties, and last year Ankara hosted months of indirect talks between Israel and Syria after an eight-year breakdown.

But tensions soared after Turkish Prime Minister Recep Tayyip Erdogan stormed out of a high-profile conference where he confronted Israel’s president over steep Palestinian civilian casualties in Gaza.