Washington (CNN)North Korea is "building new missiles, new capabilities, new weapons as fast as anybody on the planet," and learning from its mistakes as it makes advances in its missile programs, the No. 2 general at the Pentagon said Friday.
Air Force Gen. John Hyten, the vice-chairman of the Joint Chiefs of Staff, made the comments as talks between Washington and Pyongyang over North Korea's nuclear program have stalled and Kim Jong Un has signaled he may be ready to test more missiles that could be capable of hitting the United States.
"If you want to go fast in the missile business you need to test fast, fly fast and learn fast. Look at Space X in this country. There were some pretty spectacular failures. Did they stop? No," Hyten said while speaking at the Center for Strategic & International Studies in Washington.
"That is what North Korea has been doing and North Korea has been building new missiles, new capabilities, new weapons as fast as anybody on the planet with the 115th most powerful economy in the world. Speed itself is efficiency," he added.
The Trump administration has reached out to North Korea to resume diplomatic negotiations after the two countries broke off talks in October, White House national security adviser Robert O'Brien told Axios over the weekend.
"We've reached out to the North Koreans and let them know that we would like to continue the negotiations in Stockholm that were last undertaken in early October," O'Brien told the news outlet.
He added, "We've been letting them know, through various channels, that we would like to get those (negotiations) back on track and to implement Chairman Kim's commitment" to denuclearization of the Korean Peninsula".
Those comments came after North Korea's leader, earlier this month, said that there "will never" be denuclearization on the Korean Peninsula if the US "persists in its hostile policy towards" the hermit nation, according to the country's state news agency.
At a meeting of ruling party officials, Kim also said his country's long term security will be guaranteed by staying on constant alert and relying on "the powerful nuclear deterrent capable of containing the nuclear threats from the US," according to the Korean Central News Agency.
KCNA released the report at the end of "The 5th Plenary Meeting of the 7th Central Committee of the Workers' Party of Korea." In the plenary, Kim said "the DPRK will steadily develop necessary and prerequisite strategic weapons for the security of the state until the US rolls back its hostile policy towards the DPRK and lasting and durable peace-keeping mechanism is built".
In an indication that North Korea could soon resume nuclear weapon testing, Kim said his country should no longer feel bound by its self-imposed halt on nuclear weapons and long-range missile testing. He also announced that "the world will witness a new strategic weapon" in the near future, KCNA reported.
Still, President Donald Trump has told reporters he remains optimistic about the future of diplomacy and touted his relationship with Kim.
"He likes me, I like him, we get along," he said. "He did sign an agreement talking about denuclearization. ... I think he's a man of his word, so we're going to find out," Trump said earlier this month.
Kim's latest threat came as American officials were closely monitoring North Korea following its promise in December to deliver a "Christmas gift" to the US.
The specific language -- North Korea referred to its first successful intercontinental ballistic missile (ICBM) launch in 2017 as a "gift" -- sparked speculation that Pyongyang could do something equally provocative, though the holiday came and went without any weapons test.
CNN's Barbara Starr, Jamie Crawford and Devan Cole contributed reporting