Obama fears nuke threat in Manhattan more than 'regional power' Russia

President Barack Obama's biggest fear is a nuclear weapon going off in Manhattan than Russia as a 'regional power'.

The comments from Obama came at a press conference in the Netherlands, where he was asked if 2012 challenger Mitt Romney was right that Russia is the United States' number one political foe, after its annexation of Crimea.

Obama said Russia's actions were a problem, but did not pose the number one national security threat to the United States, adding that he was more concerned about America's security with the prospect of a nuclear weapon going off in Manhattan.

According to news.com.au, Obama called Russia a 'regional power that is threatening some of its immediate neighbours, not out of strength, but out of weakness'.

Obama, while speaking with Dutch Prime Minister Mark Rutte after a nuclear security summit in The Hague, claimed that Russia's seizure of Crimea is 'not a done deal' and called for the international community to require Moscow to pay costs for its action.

He added that Russia's actions in Crimea could not be recognized.