North Korea’s announcement that it had deployed a new kind of tactical short-range ballistic missile on Friday illustrated the nuclear-armed state’s military advancements and pushed it to the top of new US President Joe Biden’s foreign policy agenda.

The United States condemned Thursday’s launches, which came hours before Biden held his first White House press conference since taking office in January.

When asked if he agreed that North Korea was the top foreign policy issue he faced, Biden replied: “Yes.”

Biden had previously left North Korea entirely out of his inaugural foreign policy speech in February, and his secretary of state didn’t mention it at all in a list of eight diplomatic goals released earlier in March, except to mention it as one of several countries that pose a threat.

The launches, which were North Korea’s first ballistic missile tests in nearly a year, underscored steady progress in its weapons programme since denuclearization talks with the United States floundered under former President Donald Trump.

Biden said the United States remained open to diplomacy with North Korea despite its missile tests, but warned there would be responses if Pyongyang escalates matters.

South Korea’s President Moon Jae-in called the missile test “concerning,” saying Seoul, Pyongyang and Washington should not create hurdles for talks.

“Now is the time for the South, the North and the United States to make efforts to continue dialogue. It is never desirable to create difficulties for dialogue,” he told a ceremony commemorating soldiers who fought in clashes with the North in 2002 and 2010.

North Korea had been widely expected to conduct some kind of weapons test in the early months of Biden’s term as a way of signaling its resolve, gaining practical military capabilities, and boosting its leverage should talks resume.

While North Korea’s intentions were not yet entirely clear, Thursday’s tests were relatively restrained, said John Delury, a professor at South Korea’s Yonsei University.

“These tests come some time after Biden’s inauguration, and they are still at a low enough level that it gives the administration breathing room,” he said. “Regardless of North Korea’s intentions, however, the effect is to elevate the significance and move it up the administration’s agenda.”

The State Department said the launches violated multiple U.N. Security Council resolutions and threatened the region and the broader international community.