Trump 'not sure' about letting Ukraine build Patriot missiles: FT

US President Donald Trump said he was "not sure" whether Washington will allow Ukraine to build Patriot surface-to-air interceptor missiles, the Financial Times reported on Thursday.

The issue, considered a top priority for Kyiv, was discussed when Trump met Ukraine's leader Volodymyr Zelensky at the White House this week.

Trump told FT in a phone interview that he was "not sure" about the issue, adding that "we're looking into it."

"It's a very extraordinary weapon, and . . . we have to be a little bit careful of who we licence to. We don't really licence equipment," the Republican president was quoted as saying.

Russia has stepped up its ballistic missile strikes on Ukraine, and only the American Patriot systems are capable of shooting them down.

Earlier in the month, Trump had expressed his intention to allow Ukraine to produce Patriot interceptors.