North Korea's unprecedented missile provocations have done little but solidify the United States' cooperation with South Korea and Japan, Secretary of State Antony Blinken said Friday, insisting that US alliances have only grown stronger over the years.

The top US diplomat also called on China to help bring North Korea back to the dialogue table, insisting that failure to do so will not benefit anyone, including China.

"We have channels of communication. We have used them, and we made clear going back to early in this administration that we were prepared to have negotiations with North Korea on the nuclear program with no preconditions," Blinken said while speaking at an annual security forum hosted by the Aspen Institute, a nonprofit organization based in Washington.

"We sent that message several times. Here is the response we got: one missile launch after another," he added.

North Korea fired an unprecedented 69 ballistic missiles in 2022, the largest number of ballistic missiles launched in any given year. Pyongyang also test fired a new solid-fuel intercontinental ballistic missile last week, marking its 12th ICBM launch since the start of last year.

The US has not stood still, insisted Blinken.

"The partnership, the alliance that we have with Japan and with South Korea has grown even stronger, even deeper, and we have taken further steps to make sure that we could defend ourselves, defend our allies and partners, deter any aggression coming from North Korea," he told the seminar.

"So, in effect, the response that North Korea has elicited with these repeated provocations is only been to solidify the work the United States, Korea and Japan are doing together to make sure we can defend ourselves," added Blinken.

The secretary said he also called on his Chinese counterparts during his recent trip to Beijing to help bring North Korea to the dialogue table.

"And what I shared with Chinese counterparts is this: we believe that you have unique influence and we hope that you will use it to get better cooperation from North Korea. But if you can't, or if you won't, then we are going to have to continue to take steps that are directed to China but that China probably won't like because it goes to strengthening and shoring up not only our own defenses, but those of Korea and Japan," he said.

When asked about the US service member who crossed the inter-Korean border into North Korea earlier this week, Blinken said the U.S. has yet to learn of his whereabouts or his wellbeing.

"We are very concerned, of course, about his well being. We would like to know his whereabouts," said Blinken, pointing to the way those detained in North Korea had been treated in the past.

"We communicated to North Korea seeking that information. I don't have anything more at this point," he added.