SEOUL - South Korea Wednesday delivered 20 tons of powdered milk for North Korean children despite tensions over a major military exercise south of the border, Seoul officials said.

The cross-border shipment is part of a promised Red Cross aid package also including 10,000 tons of corn, said unification ministry spokeswoman Lee Jong-Joo.

"The purchase of 10,000 tons of corn is now under way," Lee said.

In addition to food aid for the hungry North, the South sent drugs and other material to fight swine flu in December and February.

The North has reacted angrily to an annual 10-day military exercise launched Monday by US and South Korean troops. It sees the war games as a rehearsal for invasion.

The North said Monday it had ordered its military on full alert and announced readiness to "blow up" South Korean facilities in response to aggression.

The communist state said Tuesday it would strengthen its nuclear deterrent in response to US military threats and is prepared for both dialogue and war with Washington.

The US and South Korea say the Key Resolve/Foal Eagle exercise, which this year involves 18,000 American and 20,000 South Korean troops, is defensive.

The North habitually responds angrily to the war games south of the border but they normally pass off without major incident.

This year's exercise coincides with diplomatic efforts to bring the North back to six-nation nuclear disarmament talks which it quit last April, a month before staging a second atomic weapons test.

As a precondition for returning, it demands a US commitment to open talks about a peace treaty to replace the armistice that ended the 1950-53 Korean War. The North also calls for UN sanctions to be lifted.

-AFP