Instead, the United States will be represented by Deputy Secretary of State Christopher Landau during Wednesday's meeting, news agencies AFP and Reuters report, among others.
According to The Wall Street Journal, this is the first time since 1999 that the United States has not sent its Secretary of State to a regular NATO foreign ministers meeting.
However, Secretary General Mark Rutte has no problem with Rubio having other things on his mind.
"I completely accept that he is not here tomorrow," Rutte said at his press conference ahead of the foreign ministers' meeting.
He also promises continued "unwavering" support for Ukraine, but also keeps his fingers crossed for future peace.
"We welcome the peace efforts led by the US to make this a reality. We must stop the 'meat grinder'. I have full confidence in what the Americans are trying to achieve," Rutte said in Brussels.
Wednesday's meeting is seen in part as an initial preparation for the next NATO summit to be held in Ankara, Turkey, in July 2026. In addition, a special meeting of NATO's Ukraine Council will be held, also with the participation of Ukrainian Foreign Minister Andriy Sybiha and EU High Representative Kaja Kallas.
