About 300 U.S. marines participated in a live-firing exercise to demonstrate their skills with three howitzers north of Seoul.

[Captain Jarrod Graham, U.S. Commanding Officer of Battery]:
"The objective for this training is to show our support for the Republic of Korea through training here at a Rodriguez Range as well as to get a good training out of being able to go to different area besides Camp Pendleton in support of our infantry."

The military drills are aimed at testing the allies' defense readiness, include training the special forces to cope with the North's nuclear arsenal.

This is the second time that the special units were deployed to participate in the drills.

The operations draw fiery response from the North each year and fuel tensions on the Korean peninsula despite the fact they have been held for decades without major incident.

The drills involve about 18-thousand U.S. troops, with 8,000 coming from abroad and 10,000 already stationed in the South.

The South's Defense Ministry says about 20-thousand of its troops will participate in the drills.

The two Koreas are technically still at war because their 1950-53 conflict ended with an armistice and not a peace treaty.