North Koreainfo-icon accused the United Statesinfo-icon on Tuesday of pushing the Korean peninsula to the brink of nuclear warinfo-icon after a pair of strategic U.S. bombers flew training drills with the South Korean and Japanese air forces in another show of strength.

The two supersonic B-1B Lancer bombers were deployed amid rising tensions over North Korea's dogged pursuit of its nuclear and missileinfo-icon programmes in defiance of United Nationsinfo-icon sanctions and pressure from the United States.

The flight of the two bombers on Monday came as U.S. President Donald Trumpinfo-icon said he was open to meeting North Korean leader Kim Jong Un in the appropriate circumstances, even though Pyongyang suggested it would continue with its nuclear tests.

South Korean Defence Ministry spokesman Moon Sang-gyun told a briefing in Seoul that Monday's joint drill was conducted to deter provocations by the North and to test readiness against another potential nuclear test.

The U.S. air force said in a statement the bombers had flown from Guam to conduct training exercises with the South Korean and Japanese air forces.North Korea said the bombers conducted "a nuclear bomb dropping drill against major objects" in its territory at a time when Trump and "other U.S. warmongers are crying out for making a preemptive nuclear strike" on the North.

"The reckless military provocation is pushing the situation on the Korean peninsula closer to the brink of nuclear war," the North's official KCNA news agency said on Tuesday.Tensions on the Korean peninsula have been high for weeks, driven by concerns that the North might conduct its sixth nuclear test in defiance of pressure from the United States and Pyongyang's sole major ally, Chinainfo-icon.

China's Global Times, a state-backed tabloid that does not necessarily reflect national policy, said in an editorial late on Monday the United States should not rely on China alone to pressure Pyongyang into giving up its nuclear ambitions.

April could prove a "turning point", the paper said, but "Washington ... must also continue to exert its own efforts on the issue".It was widely feared North Korea could conduct its sixth nuclear test on or around April 15 to celebrate the anniversary of the birth of the North's founding leader, Kim Il Sung, or on April 25 to coincide with the 85th anniversary of the foundation of its Korean People's Armyinfo-icon.

The North has conducted such tests or missile launches to mark significant events in the past.Instead, North Korea conducted an annual military parade, featuring a display of missiles, on April 15 and then a large, live-fire artillery drill 10 days later.

Meanwhile, the Terminal High Altitude Defense system set up at a converted golf course in Seongju has "early capability" to respond to North Korea's nuclear and missile threat, Defense Ministry spokesman Moon Sang Gyun said. He didn't say when Washington and Seoul expected THAAD to be operating fully.The deployment has triggered anger from Seongju residents who fear North Korea may target their town and who worry about rumored healthinfo-icon hazards linked to THAAD's powerful radar.

People also debate whether the security benefits of THAAD would outweigh drawbacks if relations worsen with China, which sees the system as a threat, and they have been angered by President Donald Trump's statement that he would make South Koreainfo-icon pay $1 billion for the system.

The THAAD battery had originally been scheduled to enter operation by the end of the year. When completed, it will consist of six truck-mounted launchers that can fire up to 48 interceptors toward incoming missiles detected by the system's x-band radar.

Critics question whether the United States and Seoul's caretaker government are rushing to set up THAAD before an election May 9 that will bring a change in the government in Seoul, which became necessary after Park Geun-hye was impeached and ousted from the presidency in a corruptioninfo-icon scandal.

Front-runner Moon Jae-in, a liberal who calls for engagement with North Korea, has said he would reconsider THAAD if he becomes president.

North Korea conducted another missile test on Saturday, its third launch in April alone, which reportedly failed soon after launch, and its Foreign Ministry said Monday the country will speed up measures to bolster its nuclear program "at the maximum pace."