Kim also said North Korea was no longer obligated to maintain a self-imposed suspension on the testing of nuclear weapons and intercontinental ballistic missiles, which President Donald Trump has touted as a major diplomatic accomplishment. But Kim gave no clear indication that a resumption of such tests was impending and appeared to leave the door open for eventual negotiations.
Kim has used the diplomatic stalemate to expand his military capabilities by intensifying tests of shorter-range weapons. His arsenal is now estimated to include 40-50 nuclear bombs and various delivery systems, including solid-fuel missiles designed to beat missile-defense systems and developmental ICBMs potentially capable of reaching the U.S. mainland.
Kim has also strengthened his negotiating position, moving the diplomacy closer to an arms reduction negotiation between nuclear states rather than talks that would culminate in a unilateral surrender of the weapons he sees as his strongest guarantee of survival.
Lee Sang-min, spokesman for South Korea's Unification Ministry, said North Korea carrying out its threat to showcase a new strategic weapon would be unhelpful for diplomacy.
Strategic weapons usually refer to nuclear-capable delivery systems such as ICBMs, but North Korea otherwise has been vague about what new arms it would display. It announced in December that it performed two "crucial" tests at its long-range rocket launch site that would further strengthen its nuclear deterrent.
Kim's comments published in state media Wednesday were made at a key, four-day meeting of the ruling Workers' Party's Central Committee as talks between Washington and Pyongyang have faltered over disagreements on disarmament steps and the removal of sanctions.
Some experts say North Korea, which has always been sensitive about electoral changes in U.S. government, will avoid serious negotiations in the coming months as it watches how Trump's impending impeachment trial over his dealings with Ukraine affects U.S. presidential elections in November.
Kim may instead seek to strengthen his leverage by promoting a united front with Beijing and Moscow, Pyongyang's traditional supporters, which seek to establish themselves as major stakeholders in North Korean diplomacy. Both have called for the U.N. Security Council to consider easing sanctions on the North to spur progress in nuclear negotiations.
Kim last year had said the North would pursue a "new way" if the Trump administration doesn't make concessions to salvage the negotiations by the end of December. Kim's defiant words entering 2020 indicate his "new way" could look very much like the one — a patient determination to wait out sanctions and pressure, which will possibly weaken over time, while cementing the country's status as a nuclear state.
Kim at the party meeting declared the North will never give up its security for economic benefits in the face of what he described as increasing U.S. hostility and nuclear threats, the Korean Central News Agency said.
"(Kim) said that we will never allow the impudent U.S. to abuse the DPRK-U.S. dialogue for meeting its sordid aim but will shift to a shocking actual action to make it pay for the pains sustained by our people so far and for the development so far restrained," the agency said, referring to the North by its formal name, the Democratic People's Republic of Korea.
Kim added that "if the U.S. persists in its hostile policy toward the DPRK, there will never be the denuclearization on the Korean Peninsula and the DPRK will steadily develop necessary and prerequisite strategic weapons for the security of the state until the U.S. rolls back its hostile policy," KCNA said.
"(Kim) confirmed that the world will witness a new strategic weapon to be possessed by the DPRK in the near future, declaring that we cannot give up the security of our future just for the visible economic results ... now that hostile acts and nuclear threat against us are increasing," it said.
Trump late Tuesday urged Kim to stick to his alleged commitment to denuclearize. The leaders after their first summit in Singapore in June 2018 issued a vague statement on a nuclear-free Korean Peninsula without when and how it would occur.
"Look, he likes me, I like him, we get along," Trump said as he walked into a New Year's party at Mar-a-Lago. "But he did sign a contract, he did sign an agreement talking about denuclearization ... I think he's a man of his word so we're going to find out, but I think he's a man of his word."
North Korea has held to its self-imposed moratorium on nuclear and ICBM testing since 2018, though last year it ended a 17-month pause in ballistic activity by testing a slew of solid-fuel weapons that potentially expanded its capabilities to strike targets in South Korea and Japan, including U.S. military bases there.
While Kim gave no clear indication he was abandoning negotiations entirely or restarting the suspended tests, he said North Korea's efforts to bolster its deterrent will be "properly coordinated" depending on future U.S. attitudes.
Koh Yu-hwan, a North Korean expert at Seoul's Dongguk University, said it would be irrational for Pyongyang to risk shattering its negotiations with Washington by resuming ICBM tests when Beijing and Moscow are campaigning for eased sanctions.
"When you are developing an unfinished nuclear program, you conduct test after test in efforts to manufacture a crisis that would force your rival into negotiating, which was North Korea's previous pattern of behavior," said Koh, an adviser to South Korean President Moon Jae-in.
"But once you reached a strategic (nuclear) status and need to consolidate it, you do it quietly while holding back provocative tests, like the way India and Pakistan did it," Koh said.
Kim did warn there were no longer grounds for the North to be "unilaterally bound" to its moratorium, criticizing the United States for expanding sanctions, continuing military exercises with South Korea and providing the South with advanced weaponry.
The allies have scaled down their major military exercises since 2018 to create space for diplomacy, but North Korea considers such drills to be rehearsals for an invasion and insists even the smaller drills violate agreements between the leaders. The North has also criticized the allies over South Korea's recent acquisition of advanced U.S. F-35 fighter jets.
The extensive KCNA report from the party meeting may have replaced a New Year's speech like Kim has given in past years announcing major changes in security and economic policies. No speech was broadcast as of Wednesday afternoon, though Koh said a broadcast or statement could come later.
Kim touched on economic issues in his remarks to the party meeting, saying his nation was prepared for a "long confrontation" with the United States and vowing to build "internal strength" to withstand sanctions.
Kim called for his people to stay resilient in a struggle for "self-reliance" a nd lamented unmet goals in economic objectives laid out in 2019, calling for significant improvements in agricultural production and removal of unspecified "evil practices and stagnation" across industries including coal mining, electricity production, machinery and railway transport.