This should not be necessary, but
Manchester police name suspect in concert bombingGreater Manchester Police Chief Constable Ian Hopkins said authorities believe the attack was carried out by 22-year-old Salman A., but declined to go into further details because he had not been formally identified.
Snopes has a similar article but it's by AP, who don't like their work being quoted, even in brief fair-usage-compliant manner.
There are several articles "out there" making the Trump-leaked claim, but it's absurd on its face. The bombing happened in Manchester,
England, not in the US, where the FBI would be involved. There is no reason reason Manchester police or any other UK authority would give the suicide bomber's name to high-level Trump Administration people, and probably not to any counter-terror people in the US. It probably started with some Hate-Trumper at the (Manchester) Guardian posting this wild-ass claim, knowing Hate-Trump media would repeat it without first fact-checking it.