U.S. President Donald Trump has seized on Americans' growing animosity toward China over the coronavirus outbreak to underpin his re-election pitch, arguing he will hit Beijing harder than anyone.

That is just tough talk hardly substantiated by action, says Jake Sullivan, a senior adviser to presumed Democratic presidential nominee Joe Biden.

Biden's campaign is preparing to roll out policies on how his future administration would better deal with China and will continue to show how Trump is weak on America's top geopolitical and economic competitor, Sullivan told Reuters in an interview.