The claim is supported by multiple web search results detailing Trump's statements about not using nuclear weapons because conventional means had already 'decimated' Iran, and that such weapons should never be used. However, the evidence provided does not allow for confirmation from two or more independent source *organizations* reporting this specific combination of statements.

The evidence provided contains general information about US/Iran relations and negotiations, but none of the retrieved snippets directly corroborate the specific claim that the US president boasted about the scale of damage *and* suggested Tehran's rearmament could be neutralized in 'about one day'. The evidence is too general to confirm this specific boast.