A U.S. B-1 strategic bomber joined South Korean and U.S. fighter jets in a training mission over the Korean peninsula on Wednesday, dropping a guided JDAM weapon used with so-called bunker-busting munitions, the South’s defence ministry said.

The drill comes a day after South Korea said it was resuming all military activities along the border with the North after suspending their 2018 military pact that aimed at easing tension and preventing military clashes.

The JDAM, or Joint Direct Attack Munition, was being used around the peninsula for the first time in seven years in an exercise demonstrating its precision strike capabilities, the ministry said in a statement.

It makes use of a guidance system that converts unguided free-fall bombs, including the BLU-109 penetrator warhead, into precision munitions using a navigation and control unit, the U.S. Air Force said.

The ministry did not specify the location of the training flight. South Korean F-15K fighters flying with the B-1 carried out live firing in the drills in which U.S. and South Korean Stealth F-35 jets and F-16s also participated, it said.

The resumption of military activities was a response to the North’s launch of hundreds of balloons carrying trash into the South, which called the move an unacceptable provocation that left it no choice but to suspend the military pact.

North Korea had said last year it was no longer bound by the agreement.

South Korea’s Marines plan a live-fire exercise on remote west coast islands near the maritime border disputed by the North, making use of K-9 mechanised artillery, a South Korean government source said on Wednesday.

The sensitive sea border has been the scene of deadly clashes in the past between South and North Korean artillery units and naval vessels.

The South Korean and U.S. militaries have stepped up training exercises in response to North Korea’s weapons testing, including ballistic missile launches and tactical weapons firing.

(Reuters)