North Korea fired off an apparent intermediate-range ballistic missile (IRBM) on Monday in its first launch of the year, the South Korean military said, as U.S. Secretary of State Antony Blinken traveled to Seoul for what was likely his final visit to the region as top diplomat.

South Korea's military said in a statement that the North had fired off what it believed was an IRBM toward the Sea of Japan from the Pyongyang area at around noon, with the weapon traveling some 1,100 kilometers (683 miles).

The South Korean Joint Chiefs of Staff said that allied intelligence authorities had monitored the North's preparations for the missile launch and "immediately detected and tracked" it, sharing relevant information with Japan.

A South Korean military official said that the weapon was believed to be similar to North Korea's IRBMs tipped with hypersonic warheads that were launched in January and April last year, the Yonhap news agency reported.

Missiles carrying hypersonic warheads are seen as more capable of evading defenses than conventional ballistic missiles thanks to their ability to change direction midflight.

If confirmed to be a hypersonic missile, Yonhap reported, it would be the farthest distance covered by a North Korean missile of its kind.

Japan's Defense Ministry, meanwhile, also confirmed the launch of an unspecified ballistic missile, saying, too, that it had traveled about 1,100 km at an altitude of about 100 km before splashing down just outside Japan's exclusive economic zone (EEZ).

The ministry said in a statement that Japan was working closely with the U.S. and South Korea to analyze the launch.

"The series of actions taken by North Korea, including the repeated launches of ballistic missiles, threaten the peace and security of our country, the region and the international community," the ministry said in the statement, adding that Tokyo had "strongly protested and condemned" the move.

The launch came as Blinken visited Seoul for a meeting with his counterpart and South Korea's acting president as part of a bid to encourage stability in the U.S. ally — including in its much-improved relations with Japan.

Speaking at a news conference hours after the launch, Blinken said it had highlighted the importance of trilateral security cooperation.

"Today's launch is just a reminder to all of us of how important our collaborative work is," he said.

Blinken's trip also came the day an arrest warrant for impeached President Yoon Suk Yeol was set to expire, with authorities seeking an extension of the warrant for the impeached leader.

The top U.S. diplomat was looking to shore up ties ahead of President-elect Donald Trump's return to the White House on Jan. 20.

In a signal to Trump, North Korea used a key party meeting overseen by leader Kim Jong Un late last month to announce its “toughest” ever strategy to counter the United States, Pyongyang's state-run media said.

Monday's launch was Pyongyang's first since Trump was elected on Nov. 5. The North last fired off a missile just hours before U.S. voters headed to the polls, sending multiple short-range weapons into waters outside Japan's EEZ.