North Korea fired a suspected intermediate-range ballistic missile towards the sea on Sunday, South Korea’s military said – its first launch this year.

The move came two months after the North claimed to have tested engines for a new harder-to-detect missile capable of striking distant US targets in the region.

Experts have said North Korea could ramp up its provocative missile tests as a way to influence the results of South Korea’s parliamentary elections in April and the US presidential election in November.

South Korea’s Joint Chiefs of Staff said in a statement that it detected the launch of a ballistic missile of an intermediate-range class from the North’s capital region on Sunday afternoon. It said the missile flew toward the North’s eastern waters.

South Korea, the US and Japan are analysing further details of the launch as the South’s military maintains readiness, according to the statement.

Japan’s Defence Ministry also said it spotted the North’s possible ballistic missile.

The Japanese coast guard, quoting the Defence Ministry, said the suspected missile is believed to have landed in the ocean.

In mid-November, North Korea’s state media said it had successfully tested solid-fuel engines for a new intermediate-range ballistic missile that observers say is likely designed to hit US military bases in Okinawa, Japan, and the US Pacific territory of Guam.

Built-in solid propellants make missile launches harder for outsiders to detect than liquid-fuelled missiles, which must be fuelled before launch and cannot last long.

North Korea has a growing arsenal of solid-fuel short-range missiles targeting South Korea, but its existing intermediate-range missiles, including the Hwasong-12, are powered by liquid-fuel engines.

The last time North Korea carried out a public missile launch was on December 18, when it test-fired its Hwasong-18 solid-fuelled intercontinental ballistic missile, the North’s most advanced weapon. The Hwasong-18 is the North’s only known solid-fuel ICBM and is designed to strike the mainland US.

In recent days, North Korea has also been escalating its warlike, inflammatory rhetoric against its foes.

Leader Kim Jong Un, during visits to munitions factories last week, called South Korea “our principal enemy” and threatened to annihilate it if provoked, the North’s state media said on Wednesday.

On January 5, North Korea fired a barrage of artillery shells near the disputed western sea boundary with South Korea, prompting South Korea to carry out similar firing exercises in the same area.

South Korea accused North Korea of continuing similar artillery barrages in the area for the next two days.

The site is where the navies of the two Koreas have fought three bloody sea battles since 1999 and attacks blamed on North Korea killed 50 South Koreans in 2010.

Experts say Mr Kim is likely to want to see South Korean liberals pursue rapprochement with North Korea while maintaining a parliamentary majority status and for former US president Donald Trump to be elected again. They say Mr Kim might believe he could win US concessions like sanctions relief if Mr Trump returns to the White House.

In a key ruling party meeting in late December, Mr Kim vowed to expand his nuclear arsenal and launch additional spy satellites to cope with what he called US-led confrontational moves.