The two neighbouring nations have encountered friction in their ties after Poland – that has been one of Ukraine’s fiercest allies through the course of Russian invasion – decided to extend a ban on Ukrainian grain imports.
Last week, Poland said it would only carry out previously agreed arms deliveries to Ukraine and choose to focus on rebuilding its own weapons arsenal.
“I’m expecting and I’m confident that Ukraine and Poland will find a way to address those issues without that impacting in a negative way the military support to Ukraine,” Mr Stoltenberg said in an interview in Copenhagen on Friday.
The announcement coincided with tensions peaking between the two neighbours after Ukraine president Volodymyr Zelensky said some countries were “feigning solidarity by indirectly supporting Russia” with a ban on grain imports.
After Russia launched a full-scale invasion of Ukraine last February, a majority of Ukrainian grain ended up in Europe as the main Black Sea shipping lanes all but closed.
Imports were then blocked by five countries to try and protect EU farmers amid fears the amount of grain would drive down local prices. Poland extended the ban after the European Union-brokered deal expired last week.
On Tuesday, Mr Zelensky repeated his accusation on Eastern European nations backing Russia during his speech at the UN General Assembly.
Poland then summoned the Ukrainian ambassador to its foreign ministry to protest Mr Zelensky’s comments. Hours later, Warsaw announced it would no longer be supplying weapons to Ukraine.
“We are no longer transferring weapons to Ukraine, because we are now arming Poland with more modern weapons,” the prime minister said.
Poland has previously sent 320 Soviet-era tanks and 14 MiG-29 fighter jets to the war-torn country.
Mr Morawiecki also issued a warning to Kyiv, saying if they “escalate the conflict”, additional products will be added to the list of banned imports.
“I am warning Ukraine’s authorities. Because if they are to escalate the conflict like that, we will add additional products to the ban on imports into Poland,” he said.
“Ukrainian authorities do not understand the degree to which Poland’s farming industry has been destabilised. We are protecting Polish farmers.”
Ukraine’s other ally Slovakia is also seeing discussions of halting support to Ukraine.
The Nato nation has been a staunch ally of Kyiv and sent military equipment including MiG-29 fighter jets and an S-300 air defence system to its neighbour.
But opposition leader and former prime minister Robert Fico has pledged to end that military support.
Mr Fico is leading polls ahead of Saturday’s election.
“Whatever new government they will have in Slovakia, we will continue to sit down at Nato meetings,” Mr Stoltenberg said, “and I’m confident that we’ll find ways to continue to provide support – as we have been after every election in this alliance since the war started”.