Poland is only carrying out supplies of ammunition and weapons to Ukraine that were agreed to before Warsaw made a decision to stop weapons shipments to its neighbor, government spokesperson Piotr Muller said Thursday, according to state news agency PAP.

Muller emphasized that Ukraine has made a series of "absolutely unacceptable statements and diplomatic gestures" and that "Poland does not accept this type of unjustified actions," according to PAP.

In his remarks at the UN General Assembly on Tuesday, Zelensky said "it is alarming to see how some in Europe, some of our friends in Europe, play out solidarity in a political theater – making a thriller from the grain," adding "they may seem to play their own role but in fact they are helping set the stage to a Moscow actor."

On Wednesday, Polish Prime Minister Mateusz Morawiecki said that Poland will stop providing weapons to Ukraine, a change of policy that comes as tensions between Ukraine and its close ally rise over a temporary ban on Ukrainian grain imports to certain EU countries.

Poland also "urgently summoned" the Ukrainian ambassador to Warsaw Vasyl Zvarych on Wednesday over Zelensky's comments, and Poland's Deputy Foreign Minister Pawel Jablonski told Zvarych that Zelensky's "thesis is untrue in relation to Poland."

Some context: The ban on Ukrainian grain was initially put in place earlier this year by several European Union nations to protect local farmers, who were worried about being undercut by the low prices of Ukrainian grain. 

Last week, the EU announced plans to suspend the ban, but Poland, Hungary and Slovakia said they intended to defy the change and keep the restrictions in place.