SEOUL/TOKYO, Oct 31 (Reuters) - North Korea conducted what appeared to be its longest ever intercontinental ballistic missile test on Thursday as South Korea warned Pyongyang could seek missile technology from Russia in exchange for deploying troops to help with the war in Ukraine.

The missile was launched on a sharply lofted trajectory from an area near the North's capital and splashed down about 300 km (190 miles) west of Japan's Hokkaido, recording the North's longest ever ICBM flight time.

The muscle-flexing by Pyongyang came a day after Seoul reported signs the North may test-launch an ICBM or conduct a seventh nuclear test around the U.S. presidential election on Tuesday, seeking to draw attention to its growing military prowess.

The launch drew swift condemnation from South Korea, Japan and the U.S., coming amid rising international alarm over North Korea reportedly dispatching thousands of troops to Russia to support its war in Ukraine.

"It is believed the North Korea ballistic missile is a long-range ballistic missile fired at a high angle," South Korea's Joint Chiefs of Staff said in a statement.

Initial analysis points to a possible use of a newly developed solid-fuel booster, it said later in a news briefing.

According to South Korea and Japan, the missile recorded a flight-time of 87 minutes, longer than the last ICBM test launch in December 2023 which clocked at 73 minutes.

The trajectory reached an altitude of 7,000 km and flew a distance of 1,000 km, the Japanese government said, calling it an ICBM-class missile.

A U.S. official told Reuters the missile was an ICBM.

The so-called lofted trajectory of a projectile flying at a sharply raised angle is intended to test its thrust and stability over much shorter distances relative to the designed range, partly for safety and to avoid the political fallout of sending a missile far into the Pacific.

The last ICBM tested in December last year, dubbed the Hwasong-18, fuelled by solid-propellant and fired from a road launcher, was also launched at a sharply raised angle and gave a flight time that could translate to a potential range of 15,000 km (9,300 miles) on a normal trajectory.

That is a distance that puts anywhere in the mainland United States within range.