Poland’s Deputy Defense Minister Cezary Tomczyk said that his country has no objections to Ukraine using Polish weapons to hit targets in Russian territory. Similar permission was also granted by Canada and Finland. Britain was one of the first to grant permission to use its weapons in Russian territory; this position has since been supported by Lithuania, Latvia, Estonia, France, the Netherlands, Sweden, and the Czech Republic.
The US is still opposed, but pressure on the Biden administration to allow this is increasing internally and externally. According to the WP, Biden is leaning towards giving Ukraine permission to strike with American short-range weapons in Russian territory.
In turn, Putin reacted to this by declaring that “these representatives of NATO countries, especially in Europe and small countries, should realize what they are playing with.”