WASHINGTON -- US National Security Advisor Jake Sullivan met Monday with China's Yang Jiechi to discuss various current issues, including North Korea, a senior US official said.

The official, who spoke on condition of anonymity, said the meeting was "intense" and seven-hours long.

"Obviously, we have serious concerns about the recent escalatory actions that we have seen from the DPRK," the official said in a telephonic press briefing, referring to North Korea by its official name, the Democratic People's Republic of Korea.

"The national security advisor was clear with Director Yang not only about those concerns, but also about the steps that we believe are necessary in this moment and the work that we hope to be able to engage with China on," added the official.

The White House said the Sullivan-Yang meeting was held in Rome, Italy, mainly to discuss Russia's ongoing aggression on Ukraine. Yang is a member of the Politburo of the Chinese Community Party and director of the office of the foreign affairs commission.

The US said Thursday that North Korea's two missile launches, staged Feb. 27 and March 5 (Seoul time), were aimed at testing a new intercontinental ballistic missile (ICBM) system, also noting the recalcitrant country may conduct a full-fledged ICBM test in the future.

North Korea conducted nine rounds of missile tests since the start of the year, including seven in January that marked the largest number of missile launches it conducted in any single month.

White House spokesperson Jen Psaki noted the North's recent tests did not involve any "fanfare" unlike dozens of missile tests it had conducted in the past.

"We have seen North Korea escalate its testing in different periods over the last four presidents. And this time, North Korea had these tests unlike the fanfare over past tests, but I don't have anything to predict in terms of the future," she said when asked if a North Korean ICBM test was imminent.

Psaki, however, highlighted the US making a rare revelation of its intelligence.

"What I can tell you is that, as you know, last week we proactively decided to reveal information publicly about recent tests and share it with allies and partners, as well as Congress," she said.

North Korea has claimed its two missile tests on Feb. 27 and March 5 had been aimed at developing a reconnaissance satellite.

Pyongyang has often disguised its ICBM tests as satellite launches in the past, and US officials have noted it may again try to disguise its future tests as "space launches."

US Special Representative for the DPRK Sung Kim earlier called on China to condemn North Korea's missile provocations and help bring North Korea back to the dialogue table.

The senior administration official, who spoke on condition of anonymity, said Sullivan and Yang have agreed to continue their discussions, "building on recent discussions between our special representative Sung Kim and the Chinese special representative Liu Xiaoming in order to further discuss specific ways that the United States and China may be able to press the DPRK on a different path."

Pyongyang has avoided denuclearization talks since late 2019. It also remains unresponsive to recent US overtures.