North Korea fired a mid-range ballistic missile into the sea east of the Korean Peninsula on Sunday afternoon, according to South Korea’s Joint Chiefs of Staff.

This was the North’s first ballistic missile launch of the year, with the previous one on Dec. 18.

“At approximately 2:55 p.m. on this day, a single intermediate-range ballistic missile was fired from the vicinity of Pyongyang toward the east coast, flying for about 1,000 kilometers before landing in the water,” the South’s JCS said in a release.

The ballistic missile was detected and tracked from the point of the launch by the South Korean military, which is working in close coordination with the authorities of the US and Japan for a comprehensive analysis on its detailed specifications, it said.

“We strongly condemn the North Korean missile launch as a clear act of provocation that gravely threatens the peace and stability of the Korean Peninsula,” it said. “We are maintaining a full-readiness posture, and sharing information the North Korean launch with the US and Japanese authorities.”

South Korean authorities previously warned of the possibility of an imminent test after North Korea reported progress in solid-fuel engines for an IRBM in November last year. Ballistic missiles using solid-fuel engines do not have to be fueled prior to use, unlike liquid-fuel ones, allowing for a quick launch.

Shin Won-sik, Seoul’s Minister of National Defense, told a pooled interview on Jan. 10 that North Korea “appears to be continuing preparations” for a test launch of the new IRBM.

“It’s possible the test could take place early this year, if not January,” he said.

Sunday’s launch comes amid heightened tensions between the Koreas after North Korea canceled a 2018 pact with the South under which the two sides agreed to minimize military measures around the shared border. South Korean military and intelligence officials believe North Korea is likely to ramp up its weapons tests to coincide with the elections in South Korea and the US.

About a week ago, North Korea fired artillery shells near the South Korean islands close to the sea border for three consecutive days from Jan. 5.

North Korean state media said on Sunday afternoon that its Foreign Minister Choe Son-hui would visit Russia from Monday, in another development in intensifying ties between the two countries. Her three-day visit comes at the invitation of the Russian Foreign Minister Sergei Lavrov, it added.

North Korean and Russia have sought to forge closer ties amid condemnation from the international community for exchanging weapons and military technology, in violation of multiple United Nations Security Council resolutions.

In September last year, North Korean leader Kim Jong-un held a summit with Russian President Vladimir Putin at a Russian spaceport.

The US said last week that Russia recently fired additional North Korean ballistic missiles into Ukraine. Both Pyongyang and Moscow have denied accusations of such arms transfers.