SEOUL, South Korea — The U.S. special envoy for North Korea said Monday that Washington and Seoul agreed on the need for a strong response to North Korea’s recent spate of missile tests, though they remain open to dialogue with the country.

Sung Kim flew to South Korea on Monday for talks two days after North Korea conducted a new type of missile test in its 13th round of weapons firing this year. Experts say North Korea wants to advance its weapons arsenal and wrest concessions such as sanctions relief from its rivals.

Weapons tested include nuclear-capable missiles able to target both the U.S. mainland and its allies such as South Korea and Japan. There are concerns that North Korea may conduct a nuclear test soon to intensify its pressure campaign.

“We agreed on the need for a strong response to the destabilizing behavior we have seen” from North Korea, Kim told reporters after meeting with his South Korean counterpart. “(We) also agreed on the need to maintain the strongest possible joint deterrent capability on the peninsula.”

South Korean nuclear envoy Noh Kyu-duk said he and Kim shared concerns that North Korea will likely continue to engage in acts that raise regional tensions. He urged North Korea to return to talks.

Kim said the allies “have not closed the door on diplomacy” with North Korea and have “no hostile intent” toward the country. He repeated his earlier statement that the United States is ready to meet North Korea “anywhere, without any conditions.”

North Korea has so far rejected Kim’s outreach, saying the United States must first drop its hostile policy before talks can resume. Some experts say North Korea wants the U.S. to relax sanctions or suspend its regular military drills with South Korea, which it views as an invasion rehearsal.

Earlier Monday, the U.S. and South Korean militaries kicked off their springtime computer-simulated command post exercise. North Korea has previously responded to such drills with missile tests and warlike rhetoric.

North Korea said Sunday it tested a new tactical guided weapon a day earlier which would boost its nuclear fighting capability. Some analysts said the weapon is likely a short-range ballistic missile to be mounted with a tactical nuclear warhead capable of targeting South Korea.

Last month, North Korea test-fired an intercontinental ballistic missile potentially capable of reaching the U.S. homeland in its first long-range weapons test since November 2017.

U.S.-led diplomacy meant to convince North Korea to abandon its nuclear ambitions in return for economic and political rewards remain largely stalemated since 2019.