A 5% defense spending target for NATO members is looking increasingly likely as the alliance prepares for its big bang summit later in June.

U.S. Defense Secretary Pete Hegseth said on Thursday he was confident that members of the NATO alliance would sign up to Donald Trump's demand for a major boost in defence spending, adding that it had to happen by a summit later in June.

NATO countries are using creative math to meet the U.S. president’s demand to more than double annual spending, partly by expanding what counts beyond soldiers and weapons.