WARSAW, Poland (AP) — The Russian ambassador to Poland did not show up Monday for a meeting at the Polish Foreign Ministry where he had been summoned because of a Russian cruise missile that violated Polish airspace on the weekend, the Polish ministry’s spokesman said.

Russian Ambassador Sergey Andreev was to be given a note of protest after the Russian missile entered the airspace of the NATO member for 39 seconds early Sunday amid a Russian attack targeting western Ukraine.

Paweł Wroński, the Polish Foreign Ministry spokesman, told reporters in a brief statement outside the ministry that Andreev did not come to the meeting, and that his failure to appear has led the Warsaw government to wonder “whether he is able to properly represent the interests of the Russian Federation in Warsaw.”

Wroński said the Vienna Convention on Diplomatic Relations “clearly defines the duties of an ambassador in a host state.”

The Polish Foreign Ministry had said it would “demand explanations” from Russia over the violation of its airspace — the latest of several incidents since Moscow launched its war against Ukraine more than two years ago.

Polish Foreign Minister Radek Sikorski informed NATO Secretary General Jens Stoltenberg of details of the incident by phone on Monday, the ministry said in a statement.

Sikorski stressed that Russia’s war against Ukraine also threatens the security of NATO member states, the statement said.