Turkey will block a NATO plan to defend Baltic countries unless the alliance recognises a Kurdish militant group as terrorists, President Recep Tayyip Erdogan said yesterday before a London summit.

The NATO meeting, marking the alliance’s 70th anniversary, was set to be a tense affair with Turkey at odds with other members over its purchase of Russian missiles and recent offensive in northern Syria—among other issues.

It was reported last week that Ankara was blocking NATO’s new Baltic defence plan, demanding greater support in its fight against the Syrian Kurdish People’s Protection Units (YPG).

Nato has mooted a plan to bolster the defences of Poland, Estonia, Lithuania and Latvia against a potential attack from Russia, though details remain unclear.

Erdogan said he had spoken to Poland’s President Andrzej Duda on Monday and would discuss the YPG issue with Poland and the Baltic countries in London.

“With joy, we will come together and have talks on this issue,” Erdogan said at a press conference in Ankara before boarding the plane.