WARSAW, Poland • Poland’s prime minister said his country is no longer sending arms to Ukraine as a trade dispute between the neighboring states escalates and his populist party faces pressure from the far right in the upcoming national election.

Prime Minister Mateusz Morawiecki said in a television interview late Wednesday that Poland is “no longer transferring any weapons to Ukraine because we are now arming ourselves with the most modern weapons” in a military modernization plan spurred by fears of Russian aggression in the region. He did not elaborate or explain how the two actions were mutually exclusive.

A government spokesman, Piotr Mueller, clarified Thursday that the country was now only providing supplies of ammunition and armaments that had previously been agreed to, noting that “a series of absolutely unacceptable statements and diplomatic gestures appeared on the Ukrainian side.”

White House national security adviser Jake Sullivan said he believes that “Poland will continue to be a supporter of Ukraine.”

“When I read the headlines this morning, I was of course concerned and had questions, but I’ve subsequently seen the Polish government spokesman come out to clarify that in fact Poland’s provision of equipment, including things like Polish-manufactured Howitzers, is continuing and that Poland continues to stand behind Ukraine,” Sullivan said when asked about the matter at a news briefing.

Poland has supplied Ukraine with a wide range of weaponry, including Leopard 2 tanks and Soviet-era MiG fighter jets. Poles are still largely in favor of supporting Ukraine, believing their nation would be vulnerable if Russia were to prevail just across the border. But there is also a growing weariness in society with the large numbers of refugees.

Ahead of the national election on Oct. 15, the far-right Confederation party has said that Poland is not getting the gratitude it deserves for arming Ukraine and accepting its refugees. And emotions have been running high since Poland, Hungary and Slovakia announced a new ban on Ukrainian grain imports last week, saying they wanted to protect their farmers.

The Polish-Ukrainian spat comes as Ukraine forces are making slow progress breaking through Russian battle lines in a counteroffensive that has not moved as quickly or as well as initially hoped and Poland’s move could have wider fallout as another winter of fighting approaches. Kyiv’s leaders are lobbying for a new round of advanced weapons, including longer range missiles.

U.S. Army Gen. Mark Milley, chairman of the Joint Chiefs of Staff, said last weekend that there is a continued need for more weapons and equipment in Ukraine and that allies and partners are looking for ways to address that.