North Korea fired a medium-range missile on Sunday, U.S. and South Korean officials said, the latest ballistics test by a country speeding up its development of nuclear weapons and missiles.

The rocket was fired from an area near the North Korean county of Pukchang, in South Phyongan Province, and flew eastward about 500 kilometers (310 miles), said South Korea’s Joint Chiefs of Staff. The U.S. Pacific Command said it tracked the missile before it landed in the sea.

White House officials traveling in Saudi Arabia with President Donald Trump said the system that was tested, which was last launched in February, had a shorter range than the missiles fired in North Korea’s most recent tests.

An official from South Korea’s Joint Chiefs of Staff also said the missile appeared to be similar in range and apogee to the midrange missile that North Korea test-fired in February. The missile launched on Sunday reached a maximum altitude of 560 kilometers (347 miles), said the official, who spoke on condition of anonymity, citing office rules.

In February, North Korea used a launcher truck to fire a solid-fuel missile that it calls the Pukguksong (Polaris)-2, a land-based version of a submarine-launched missile the country revealed earlier. That missile traveled about 500 kilometers before crashing into the sea, according to South Korean and U.S. officials.

The February launch, the North’s first missile test after Trump took office, alarmed neighbors because solid-fuel missiles can be fired more quickly than liquid-fuel missiles, which need to be fueled before launch and require a larger number of vehicles, including fuel trucks, that could be spotted by satellites.

In an interview with “Fox News Sunday,” U.S. Secretary of State Rex Tillerson said it was too early to know whether diplomatic and economic pressures being exerted on the North Korean government are having an impact in the wake of the latest missile test.

“We’re early in the stages of applying the economic pressure as well as the diplomatic pressure to the regime in North Korea,” Tillerson said. “Hopefully they will get the message that the path of continuing their nuclear arms program is not a pathway to security or certainly prosperity. The ongoing testing is disappointing, it’s disturbing. We ask that they cease that because until they cease that testing, clearly they have not changed their view.”

South Korea’s new president, Moon Jae-in, held a National Security Council meeting to discuss Sunday’s launch, which came hours after he named his new foreign minister nominee and top advisers for security and foreign policy. He did not make a public statement after the meeting.

In Tokyo, Japanese Prime Minister Shinzo Abe called the launch a “challenge to the world” that tramples international efforts to resolve the North Korean nuclear and missile problems peacefully, and vowed to bring up the issue as the “main agenda” of this week’s G-7 summit in Italy.

The launch came a week after North Korea successfully tested a new midrange missile that it said could carry a heavy nuclear warhead. Experts said that rocket flew higher and for a longer time than any other missile previously tested by North Korea, and that it could one day reach targets as far away as Hawaii and Alaska.

Under the watch of third-generation dictator Kim Jong Un, North Korea has been aggressively pursuing a decades-long goal of putting a nuclear warhead on an intercontinental ballistic missile capable of reaching the U.S. mainland.

North Korea conducted two nuclear tests last year alone, possibly improving its ability to make nuclear weapons small enough to fit on long-range missiles. The country has also conducted a slew of rocket launches as it continues to advance its arsenal of ballistic weapons, which also include midrange solid-fuel missiles that could be fired from land mobile launchers or submarines.

If North Korea did indeed fire the Pukguksong-2 again, it might be part of attempts to stabilize the system’s functions before it operationally deploys the missiles, said Kim Dong-yub, an analyst at Seoul’s Institute for Far Eastern Studies.

Kim said there’s also a possibility that the North is conducting engine tests and other experiments as it pushes for the development of a solid-fuel intercontinental ballistic missile that could potentially reach the U.S. mainland. If the North ever obtains a solid-fuel ICBM, it would likely be a rocket powered by a cluster of several Pukguksong-2 engines, Kim said.

Missile tests such as Sunday’s present a difficult challenge to Moon, a liberal who took over as South Korea’s president on May 10 and has expressed a desire to reach out to the North. Pyongyang’s aggressive push to boost its weapons program also makes it one of the most urgent foreign policy concerns for the Trump administration, though Washington has struggled to settle on a policy.

South Korea’s Foreign Ministry said in a statement that the North’s latest launch “throws cold water” on the expectations by Moon’s government to “stabilize peace and denuclearize the Korean Peninsula.”

“Our government is open to the possibility of dialogue with North Korea, but will also maintain a stance of firmly responding to provocations,” the ministry said.

(AP)