North Korea leader King Jong Un (left) and US President Donald Trump (right) (Photo: AFP/VNA)

He added that hopefully North Korean leader Kim Jong Un will “find another path”.

US Secretary of Defense James Mattis said Thursday that diplomatic efforts to contain the threat posed by North Korea are working, and remain the favored means for solving the crisis. Mattis said war would be "catastrophic”, adding that his responsibility is to have military options should they be needed.

German Chancellor Angela Merkel has voiced opposition to violence to deal with North Korea issue. She said Germany will be intensively involved with the potential solutions that are not of a military manner, adding that escalating the rhetoric is the wrong answer. Merkel called for the close cooperation of countries involved, including the United States, China, South Korea and Japan.