Seoul, June 12 : North Korea on Friday vowed to build up a "more reliable" force against military threats from the US, saying the historic summit two years ago between leader Kim Jong-un and US President Donald Trump led to no improvement in ties between the two countries. North Korean Foreign Minister Ri Son-gwon made the remark, adding that Pyongyang would "never again" provide the US with "another package" that Trump could use to boast as his political achievements, reports Yonhap News Agency citing Pyongyang's state-media. "The secure strategic goal of North Korea is to build up more reliable force to cope with the long-term military threats from the US. This is our reply message to the US on the occasion of second anniversary of June 12," Ri said in a statement carried by the state-run Korean Central News Agency (KCNA). "What stands out is that the hope for improved relations has now been shifted into despair," he added. Ri voiced frustration over a stalemate since the Singapore summit, accusing Washington of just focusing on talking up "political achievements" without taking any actual steps to fulfil agreements. "The question is whether there will be a need to keep holding hands shaken in Singapore, as we see that there is nothing of factual improvement to be made in the relations simply by maintaining personal relations between our Supreme Leadership and the US President," he said. "In retrospect, all the practices of the present US administration so far are nothing but accumulating its political achievements. Never again will we provide the US Chief Executive with another package to be used for achievements without receiving any returns," he added. Ri's statement came hours after the US said that it is committed to implementing the Singapore summit agreement and is willing to take a flexible approach. "The US is committed to engaging North Korea in meaningful negotiations so that North Koreans can realize a brighter future," a State Department spokesperson told Yonhap News Agency in response to a request for comment on the second anniversary of the 2018 summit between Trump and Kim. "That offer remains on the table. We are willing to take a flexible approach to reach a balanced agreement on all of the Singapore summit commitments," the spokesperson added. Trump and the North's leader met in Singapore on June 12, 2018, to negotiate the dismantlement of North Korea's nuclear weapons program in exchange for sanctions relief and other concessions. The two sides also agreed to work together to improve bilateral relations, build a lasting and stable peace regime on the peninsula, and repatriate the remains of American service members killed during the 1950-53 Korean War. Trump and Kim held their second summit in February last year but failed to produce an agreement. "Unless the 70-plus-year deep-rooted hostile policy of the US towards North Korea is fundamentally terminated, the US will as ever remain to be a long-term threat to our state, our system and our people," KCNA quoted Ri as saying. /IANS