North Korea on Friday threatened to resume its nuclear weapons programme if the United States failed to lift sanctions against the country, AP reported. North Korea’s Foreign Ministry said the US President Donald Trump’s administration had failed to understand its repeated demand.

The development comes amid strained ties between South Korea and the United States over how to negotiate denuclearisation with North Korea. Seoul is of the view that Pyongyang can be encouraged towards nuclear disarmament through economic development, while Washington has set a complete shutdown of its nuclear weapons programme as a prerequisite for the lifting of sanctions, The Wall Street Journal reported.

Pyongyang said it was considering resuming “pyongjin”, its policy of advancing its nuclear weapons programme and economic development. “If the US keeps behaving arrogantly without showing any change in its stand, while failing to properly understand our repeated demand, the Democratic People’s Republic of Korea may add one thing to the state policy for directing all efforts to the economic construction adopted in April and as a result, the word ‘pyongjin’ may appear again,” the North Korean Foreign Ministry said in a statement, according to Japan Times.

In May, North Korea said it had dismantled its nuclear bomb test site in Punggye-ri as a goodwill gesture before a meeting with US President Donald Trump. During his meeting with Trump in Singapore, North Korean leader Kim Jong-un promised to work towards denuclearising the Korean peninsula. Both leaders had signed a joint statement in which the US agreed to establish diplomatic relations.

On October 7, South Korea said Washington and Pyongyang had agreed to second US-North Korean summit. On October 31, Seoul’s intelligence agency said Pyongyang appears to be preparing for possible visits by external inspectors to verify that it has shut down its nuclear test site.