美国b-52轰炸机飞抵韩国
The US is flying nuclear-capable B-52 bombers over South Korea, in what it says is a response to escalating North Korean rhetoric.
美国可携带核武器的B-52轰炸机飞抵韩国，称这是对朝鲜日益嚣张的气势的回应。
US officials said the B-52 flights demonstrated "extended deterrence（威慑，妨碍物） capabilities" amid rising tension on the peninsula.
The aircraft, which can also carry conventional weapons, flew on 8 March, with another mission set for Tuesday.
Regional tension remains high following North's third nuclear test last month.
This is not the first time that B-52 bombers have been used as part of regular military drills between the US and South Korea.
"We're drawing attention to the fact that we have extended deterrence capabilities that we believe are important to demonstrate in the wake of recent North Korean rhetoric," US Pentagon press secretary George Little said.
"As North Korea threatened to attack South Korea with nuclear weapons, the exercise involving B-52s is meaningful, as it shows US commitment to provide its nuclear umbrella on the Korean peninsula," said Kim Min-seok, spokesman for South Korea's Defence Ministry.
US Deputy Defence Secretary Ashton Carter affirmed this commitment on Monday during a visit to Seoul.