Radosław Sikorski made the comments to Poland's PAP news agency in New York after Ukrainian President Volodymyr Zelensky met with US President Donald Trump on Tuesday.
Zelensky said afterward that Trump had reacted favourably to the idea of licencing Patriot missile production to Ukraine, and that US defence firm Raytheon had signalled it was willing to cooperate.
He also said Ukraine was ready for any format of truce to protect its energy grid, with Washington expected to pressure Moscow.
Sikorski cautioned that turning such a licence into reality would not happen quickly.
"These are very complicated technologies. It requires licencing negotiations, intellectual property transfers, the construction of new factories. This is a matter of years rather than weeks or months, he said, adding he had already raised doubts about a fast rollout at a recent NATO summit in Ankara.
Asked whether the proposal could still serve as a stopgap for Ukraine in the meantime, Sikorski said: "That would be a good direction and also a sign of solidarity with Ukraine."
He said he had visited Kyiv a week earlier, where the city faces both drones—against which some defences exist—and ballistic missiles, for which he said the Patriot PAC-3 is "essentially the only way" to defend.
On a possible path to ending the war, Sikorski said he welcomed two things from Trump: his call for Russia, as the aggressor, to stop fighting, and his suggestion he might invoke sanctions legislation proposed by Senator Lindsey Graham.
"That would be a strong element of pressure on the Russian economy and finances, which are already under strain," Sikorski said.
Trump separately said he did not expect a three-way meeting with Zelensky and Russian President Vladimir Putin at the G20 summit in Miami, but said Putin was willing to meet again after their earlier talks in Alaska.
(jh/gs)
Source: PAP