 -- North Korea fired a test missile Wednesday morning, but the launch failed, U.S. and South Korean officials have confirmed.

"U.S. Pacific Command detected what we assess was a failed North Korean missile launch attempt the morning of March 22 in Korea (12:49 p.m. Hawaii time) in the vicinity of Kalma," said Cmdr. David Benham, a spokesman for U.S. Pacific Command. "A missile appears to have exploded within seconds of launch. We are working with our interagency partners on a more detailed assessment. We continue to monitor North Korea's actions closely."

South Korea's Ministry of Defense confirmed the failed launch. A ministry spokesman initially said four missiles were fired, but he later corrected that figure, saying it was one missile.

The North Korean missile was launched near Kalma in eastern Wonsan province, where North Korea previously attempted to launch its mobile-launched Musudan intermediate-range ballistic missile.

U.S. officials said that in recent days, activity was apparent in Wonsan indicating that another possible Musudan missile launch was likely.

Believed to have a minimum range of 1,500 miles, the missile is of concern to U.S. officials because mobile-launched missiles are hard to track and can be fired on short notice.

But North Korea has not had much success in testing the missile: Seven of eight Musudan launches last year were spectacular failures.

U.S. officials have still not made an assessment of what type of missile was fired in the latest launch.

In February, North Korea launched a new solid-fuel rocket that traveled 310 miles into the Sea of Japan. That launch occurred during Japanese Prime Minister Shinzo Abe's visit with President Donald Trump at his Mar-a-Lago resort in Florida.

The launch drew a sharp rebuke from both leaders, and attention-grabbing photos soon appeared showing aides prepping both leaders about the missile launch while they were at dinner.

In March, four North Korean medium-range Scud-type missiles traveled more than 600 miles, the upper limit of their range, into the Sea of Japan. Three of the missiles landed in waters in Japan’s economic exclusion zone, which extends 200 miles from its shoreline. Japanese territorial waters extend 12 miles from shore.

During a visit to South Korea last week, Secretary of State Rex Tillerson signaled a more aggressive approach to North Korea's missile and nuclear program.

"All options are on the table," particularly if North Korea continues making advances in its ballistic missile and nuclear weapons technologies, he said at a news conference in Seoul.

"If they elevate the threat of their weapons program to a level that we believe requires action, that option is on the table," Tillerson said in a comment widely interpreted to refer to the possibility of pre-emptive military force.

North Korea has stated that its goal is to develop a nuclear device small enough to be placed on a long-range missile capable of reaching the United States.

But Tillerson later indicated that the first step would be additional unilateral U.S. sanctions for North Korea or the full implementation of sanctions imposed by existing United Nations Security Council resolutions.

And on Tuesday, White House press secretary Sean Spicer described the North Korean threat as "grave and escalating," and a National Security Council official told a nuclear conference that the administration is conducting a high-priority review of North Korea policy.