upgrade to

[ostap77]

"China has strongly condemned US plans for a $5.3bn upgrade to Taiwan's US-built F-16s, calling it a "grave interference" in its internal affairs and threatened to undermine relations with the US."

Does ti mean that the Taiwanese don't have F-16s but the US government is going to lend money to buy them?

[Bennevis]

Taiwan does have them (US-built). "Upgrade" probably means just some kind of improvements, just like with computers. Researching the topic will probably help.