BRUSSELS, Belgium — NATO Secretary-General Mark Rutte highlighted the “window of opportunity” for Ukraine and urged members to continue to increase their defense contributions for the besieged country.

NATO defense ministers met in Brussels on Thursday at the alliance’s headquarters, which was followed by a meeting of the Ukraine Defense Contact Group. The UDGC announced a $1 billion weapons package for Ukraine that they will pay the United States for through the Prioritized Ukraine Requirements List, or PURL, initiative.