North Korea has fired two short-range missiles in its second weapons test in less than a week, the South Korean military says.
The missiles fired from the north-western city of Kusong travelled 420km (260 miles) and 270km towards the east.
It came hours after the top US envoy arrived in South Korea for talks on how to revive nuclear negotiations.
Analysts say the North is trying to increase pressure on the US over its failure to make concessions.
A meeting in Vietnam between North Korean leader Kim Jong-un and US President Donald Trump ended without agreement in February with the US insisting North Korea give up its nuclear programme and Pyongyang demanding sanctions relief.
The two missiles were fired at about 16:30 local time (07:30 GMT) and reached an altitude of about 50km before falling into the sea, South Korea’s Joint Chiefs of Staff said in a statement.
They were launched from Kusong, some 160km from the capital, Pyongyang. Detailed analysis was being carried out in co-operation with US intelligence officials, it added.
On Saturday, the North fired several short-range missiles, the first missile test since it launched an intercontinental ballistic missile in November 2017.
The tests should not come as a surprise as North Korean state media has repeatedly shown its frustration with recent joint US-South Korea military exercises, BBC Seoul correspondent Laura Bicker reports.
Pyongyang has also warned Washington that its patience to do a deal involving the easing of sanctions will not last long before it takes what Mr Kim has described as a “new path”, our correspondent adds.
South Korea’s presidency said the launches were “very worrisome” and unhelpful for efforts to reduce tensions.
With these latest North Korean missile tests, Pyongyang is beginning to establish a pattern.
A programme of tests is clearly underway; the aim, to send a clear diplomatic signal to the Americans (and to Seoul – it is South Korea that short-range systems can target) that the North’s patience is running out.
Last weekend, North Korea tested a new short-range ballistic missile that flew some 200 km, though experts believe its actual range may be well in excess of that.
The specific type of weapon tested in this more recent episode is not yet clear.
Pyongyang is being careful to avoid testing inter-continental range systems that would breach its understanding with the Americans. –BBC