President Donald Trump's administration has discussed holding the first US nuclear test since 1992 as a potential warning to Russia and China, the Washington Post reported Friday.
Such a test would be a significant departure from US defense policy and dramatically up the ante for other nuclear-armed nations.
One analyst told the newspaper that if it were to go ahead it would be seen as the "starting gun to an unprecedented nuclear arms race".
The report, citing one senior administration official and two former officials, all who spoke anonymously, said the discussion had taken place at a meeting on May 15.