(Reuters) - Two U.S. B-1B bombers took part in joint U.S.-South Korean military drills on Thursday, an official at Seoul’s defense ministry told Reuters, exercises which North Korea has said are taking the peninsula to the brink of nuclear war.

The planes, which scrambled from a U.S. air base in Guam, joined some 20 fighter aircraft of the two countries which have been staging a large-scale aerial exercise in South Korea since Monday, the official said.

One bomber joined the exercises on Wednesday.