BRUSSELS, March 24 – The White House has quietly assembled a team of national security officials to sketch out scenarios of how the U.S. and its allies should respond if Russian President Vladimir Putin unleashes his stockpiles of chemical, biological or nuclear weapons, The New York Times reported.

Putin may be frustrated by his lack of progress in Ukraine or determined to warn Western nations against intervening in the war, the report said.

The Tiger Team, as the group is known, is also examining responses if Putin reaches into NATO territory to attack convoys bringing weapons and aid to Ukraine, according to several officials involved in the process. Meeting three times a week, in classified sessions, the team is also looking at responses if Russia seeks to extend the war to neighboring nations, including Moldova and Georgia, and how to prepare European countries for the refugees flowing in on a scale not seen in decades.

Those contingencies are expected to be central to an extraordinary session here in Brussels on Thursday, when President Joe Biden meets leaders of the 29 other NATO nations, who will be meeting for the first time — behind closed doors, their cellphones and aides banished — since Putin invaded Ukraine.

Just a month ago, such scenarios seemed more theoretical. But today, from the White House to NATO’s headquarters in Brussels, a recognition has set in that Russia may turn to the most powerful weapons in its arsenal to bail itself out of a military stalemate.

NATO Secretary-General Jens Stoltenberg underscored the urgency of the preparation effort Wednesday, telling reporters for the first time that even if the Russians employ weapons of mass destruction only inside Ukraine, they may have “dire consequences” for people in NATO nations. He appeared to be discussing the fear that chemical or radioactive clouds could drift over the border.

One issue under examination is whether such collateral damage would be considered an “attack” on NATO under its charter, which might require a joint military response. (nyt/ez)