By Justyna Pawlak and Marek Strzelecki

WARSAW (Reuters) - Ukraine is reaping "huge political gains" from its military offensive into western Russia but the incursion is not altering the "anti-escalation approach" of the West, Polish Interior Minister Tomasz Siemoniak said.

Ukraine says it has seized more than 80 settlements over 1,150 square km (444 square miles) in Kursk since Aug. 6 in the biggest invasion of Russia since World War Two. Reuters could not independently verify the battlefield developments.

"This offensive does not change the anti-escalation attitude of the West," Siemoniak said, asked in an interview with Reuters late on Friday if Kyiv's military gains could change its allies' stance on the use of arms they supply for its war with Russia.

"I think that for Western countries this is an event in terms of changing the image of Ukraine - Kyiv's political gains are huge after less than two weeks," Siemoniak said.

The U.S. so far deems Ukraine's incursion into Kursk region a protective move appropriate for Kyiv to use U.S. equipment, officials in Washington said this week, but they expressed worries about potential complications as Ukrainian troops push further into enemy territory.

Warsaw has been one of the staunchest allies of Ukraine and Polish Prime Minister Donald Tusk struck a similar tone to Washington earlier this week, saying Ukraine had full right to carry out its war response in a way that would effectively paralyse Russia.

Russia has called Ukraine's incursion a major provocation and vowed to retaliate with a "worthy response."

The United States and Western powers, keen to avoid direct military confrontation with Russia, have said Ukraine had not given advance notice and that Washington was not involved.