North Korea fired at least two unidentified projectiles early on Thursday from an area near Wonsan, on North Korea’s eastern coast, South Korea’s Joint Chiefs of Staff said.

The projectiles flew about 430 kilometres, the Joint Chiefs of Staff said, but they did not elaborate further.

This would be the first time projectiles have reportedly been launched since U.S. President Donald Trump and North Korean leader Kim Jong-un met at the demilitarized zone between the two Koreas at the end of June.

North Korea’s last weapons testing was in May, which included both short-range missiles as well as smaller rockets. At the time, Kim oversaw the first flight of a previously untested weapon — a relatively small, fast missile that experts believe will be easier to hide, launch and manoeuvre in flight.

On Tuesday, North Korea’s state news agency, KCNA, reported that Kim inspected a large, newly built submarine while accompanied by missile program leaders. It potentially signalled continued development of a submarine-launched ballistic missile program.

Denuclearization talks between North Korea and the United States have stalled after a second summit between Trump and Kim in Vietnam in February broke down.