North Korean state media has said two new air defence missiles have been fired in a test overseen by the country’s leader Kim Jong Un.
The weapons had “superior combat capability” and used a “unique technology”, the Korean Central News Agency (KCNA) said, without adding details.
The launches, carried out on Saturday, “proved that the technological features of two types of projectiles are very suitable for destroying various aerial targets” including drones and cruise missiles, KCNA said.
The test comes hours after South Korea confirmed it fired warning shots on Tuesday at North Korean soldiers who briefly crossed the Demilitarised Zone (DMZ) separating the countries.
United Nations Command said about 30 North Korean troops crossed the heavily-fortified border between the north and south, Yonhap News Agency said.
Pyongyang responded by accusing Seoul of a “deliberate provocation”.
South Korea and the United States have been conducting large-scale joint military exercises in the region since Monday.
US President Donald Trump is due to meet South Korea’s President Lee Jae Myung at a summit on Monday in Washington.
The newly-elected South Korean president had campaigned on improving inter-Korean ties.
However, Kim’s sister has since rebuffed efforts towards reconciliation made by Lee’s government.
Kim also earlier this month condemned the US and South Korea’s joint military drills, describing them as “most hostile and confrontational”.
The North Korean leader vowed to speed up his aim to increase the country’s stash of nuclear weapons.
In January, North Korea claimed to fire a new intermediate-range ballistic missile tipped with a hypersonic warhead, which it said “will reliably contain any rivals in the Pacific region”.
Senior South Korean officials have raised concerns about North Korea receiving Russian missile technology in exchange for sending troops to back the Russian aggression against Ukraine.
Shin Wonsik, national security adviser for former South Korean President Yoon Suk Yeol, said last year that Seoul had found Moscow provided missiles and other equipment to help reinforce the air defense network for Pyongyang, the capital.
Whether the latest missiles fired by North Korea involved any Russian technology was unclear.
North Korea is one of the world’s most repressive totalitarian states, with Kim and his family ruling the hermit nation for decades.
South and North Korea have been divided since the Korean War ended in 1953.
They did not sign a peace treaty and therefore have remained technically still at war ever since, although it has been years since either side shelled the other.