GENEVA (Reuters) - North Korea and the United States accused each other on Tuesday of posing a nuclear threat, with Pyongyang s envoy declaring it would never put its atomic arsenal up for negotiation. The debate at the United Nations began when the U.S. envoy said President Donald Trump s top priority was to protect the United States and its allies against the  growing threat  from North Korea. To do so, he said, the country was ready to use  the full range of capabilities at our disposal . U.S. Ambassador Robert Wood told the Conference on Disarmament that the  path to dialogue still remains an option  for Pyongyang, but that Washington was  undeterred in defending against the threat North Korea poses . Fears have grown over North Korea s development of missiles and nuclear weapons since Pyongyang test-launched intercontinental ballistic missiles (ICBMs) in July. Those fears worsened after Trump warned that North Korea would face  fire and fury  if it threatened the United States. His remarks led North Korea to say it was considering plans to fire missiles towards the U.S. Pacific territory of Guam. Trump responded by tweeting that the U.S. military was  locked and loaded, should North Korea act unwisely . A few days later, North Korean media reported the country s leader, Kim Jong Un, had delayed any decision on whether to fire missiles towards Guam while he waited to see what the United States would do. Experts warned Pyongyang could still go ahead with the missile launches.      North Korea s ballistic missile and nuclear weapons programs pose grave threats to the entire world,  Wood told the Geneva forum.  Its recent ICBM tests are another example of the dangerous reckless behavior of the North that is destabilizing the region and beyond.  North Korea had openly stated that its missiles are intended to strike cities in the United States and its allies South Korea and Japan, he said.  My president s top priority remains protecting the homeland, U.S. territories and our allies against North Korean aggression. We remain prepared to use the full range of capabilities at our disposal against the growing threat from North Korea.  North Korea diplomat Ju Yong Chol said that measures taken by his country to strengthen its nuclear deterrent and develop inter-continental rockets were  justifiable and a legitimate option .  As long as the U.S. hostile policy and nuclear threat remains unchallenged, the DPRK will never place its self-defensive nuclear deterrence on the negotiating table or step back an inch from the path it took to bolster the national nuclear force,  Ju said. In a subsequent speech, Ju said:  The United States should clearly understand that military threats and pressure are only serving as a momentum that pushes the DPRK further into developing fully strengthened nuclear deterrence.  Regarding joint U.S.-South Korean military exercises that began on Monday, he said:  The ongoing military adventure would certainly add gasoline to the fire, driving the current tense situation to further deterioration.  China s disarmament ambassador, Fu Cong, called for support for its proposal to defuse the crisis affecting its Pyongyang ally.  China has called for  dual suspension , that is of North Korea s nuclear activities and joint military exercises between the Republic of Korea and United States. This seeks to denuclearize the peninsula and promote a security mechanism.  Wood rejected Beijing s  freeze for freeze  plan.  This proposal unfortunately creates a false equivalency between states that are engaging in legitimate exercises of self-defense who have done so for many years with a regime that has basically violated countless Security Council resolutions with regard to its proscribed nuclear and ballistic missile programs,  he told the gathering.  That is a false equivalency that we cannot accept and will not accept,  he said. Fu retorted:  I just want to say that we re not creating equivalency between anything. We are just actually making the proposal to facilitate a dialogue and to reduce the tension. We need a starting point to really launch the dialogue.  