U.S. President Barack Obama has warned that North Korea will face increased isolation and stronger sanctions if it continues to defy international agreements in pursuit of nuclear weapons.

During his first State of the Union address on Wednesday night, Obama said that diplomatic efforts will be enhanced to deal with countries that continue to seek nuclear weapons in violation of international agreements.

Obama also said that at April's Nuclear Security Summit, 44 nations will gather in Washington to secure all vulnerable nuclear materials around the world so that they never fall into the hands of terrorists.