BBC News reports: North Korea has shifted a missile with “considerable range” to its east coast, South Korea’s foreign minister says.
Kim Kwan-jin played down concerns that the missile could target the US mainland, and said the North’s intentions were not yet clear.
Pyongyang earlier renewed threats of a nuclear strike against the US, though its missiles are not believed to be capable of carrying nuclear warheads.
The US is responding to North Korea by moving missile defence shields to Guam.
The Pentagon said the shield on its Pacific island territory would be ready within weeks, adding to warships already sent to the area.
The North has previously named Guam among a list of possible targets for attack that included Hawaii and the US mainland.
Japanese and South Korea reports had suggested the missile being moved by the North was a long-range one with a capability of hitting the US west coast.
However, experts believe the North’s most powerful rocket, which it test-fired last December, has a range of 6,000km (3,700 miles) and can reach no further than Alaska.