US President Barack Obama said Thursday the United States would take firm action to prevent North Korea proliferating nuclear material to other states or terror groups. 

"The transfer of nuclear materials or material by North Korea to states or non-state entities would be considered a grave threat to the United States and our allies," Obama said in a speech to the Australian parliament. 
"We would hold North Korea fully accountable for the consequences of such action," he said. The US leader said his country would "act firmly" against any proliferation activities by North Korea and vowed that Washington's commitment to neighbouring South Korea would "never waver". 
Source: BNA