ISTANBUL — The Turkish foreign minister withdrew at the last minute from a high-profile international security conference in Munich on Friday, after learning that Israeli diplomats might take part. The abrupt move was the latest twist in a bilateral relationship between Israel and Turkey that was once friendly but has become strained and bitter.

“I was going to attend the conference, but we decided not to after Israeli representatives were later added to the session on the Middle East,” the minister, Mevlut Cavusoglu, said on TRT, the state broadcaster.

He was at pains to say that Turkey’s withdrawal was not aimed at the host country, Germany, with which Turkey has fairly strong relations even though Germany has not endorsed full membership for Turkey in the European Union.

At least 20 heads of state and other senior policy makers, including Vice President Joseph R. Biden Jr. and Secretary of State John Kerry, were expected to take part in the three-day conference on diplomatic and military issues that began Friday in Munich.