Iran already has a Nuke. Why does the US keep pressing every year?

Iran has been in the news about their nuclear program since 2007. Every year you hear from the media and US politicians that we must do something about the Iranian covert nuclear program.

Through back channels since about 2018 leaks have come to light they already possesses a couple nuclear warheads as of 2018. My question is why keep the gamesmanship up if the US intelligence communities behind close door know they already have a nuclear weapon.