U.S. President Barack Obama has stressed the need for a strong response to North Korea’s announcement that it conducted another nuclear test.

In a statement at the White House on Tuesday, Obama said the United States and the international community must unite to respond accordingly.

Obama called the North’s nuclear program “a grave threat to the peace and security of the world.”

He also said that Pyongyang's defiance of U.N. resolutions prohibiting the North from nuclear testing has further isolated the communist state and invited stronger international pressure.