South Korea and the United States began a joint maritime drill yesterday in a show of force against the North.
Key US strategic assets, including aircraft carrier USS Ronald Reagan, joined South Korean warships and anti-submarine aircraft in the exercise in waters east and west of the Korean peninsula, as US stealth planes took off in Seoul for a rehearsal ahead of an air show opening today.
China reacted cautiously to the maritime drill, which North Korea's state news agency has denounced as a "reckless act of war" that would escalate tensions to "the point of explosion".
Saying that continuing tensions on the Korean peninsula would not benefit anyone, the Foreign Ministry in Beijing urged all parties involved to "maintain restraint and work towards easing the current situation and resuming dialogue".
Russia yesterday denounced North Korea's nuclear programme, with Foreign Minister Sergei Lavrov saying Pyongyang was posing a challenge to the world.
Tensions have escalated on the Korean peninsula in the past few months after Pyongyang ramped up efforts to develop a nuclear-tipped intercontinental ballistic missile capable of striking the US mainland, prompting a heated war of words between US President Donald Trump and North Korean leader Kim Jong Un, and his aides.
Both sides, however, appear to have toned down the rhetoric recently and Pyongyang has held off fresh provocations, with key anniversaries passing without new missile or nuclear tests. The last one was conducted on Sept 15, which came about two weeks after a nuclear test.
In an interview with CNN on Sunday, US Secretary of State Rex Tillerson said Mr Trump had given him clear instructions to continue diplomatic efforts "until the first bomb drops".
White House National Security Adviser H.R. McMaster also said on Fox News that "we hope we don't have to use" military options against Pyongyang which, he said, were constantly being refined and improved upon.
Mr Trump himself said last week that he was "always open" to negotiations with Pyongyang, even though a new poll showed 46 per cent of Republicans would support a pre-emptive strike against North Korea.
South Korea's military, in the meantime, is considering developing a new operational plan to deal with "advanced threats" from the North, amid growing concerns that Seoul did not have the ability to defend itself against Pyongyang.
General Jeong Kyeong Doo, chairman of the Joint Chiefs of Staff, during a parliamentary audit report yesterday, said the military was working to develop core technologies for a rocket interception system to cope with missile threats from the North.
Analysts said the relative calm in the past few weeks could be a sign that both the US and North Korea are quietly trying to reach out to each other using diplomatic back channels.
Dr Go Myong Hyun of the Asan Institute for Policy Studies told The Straits Times: "By not conducting any provocations, North Korea is giving some space for diplomacy to take place. If they are quiet, it could be an indication that negotiations might be working."
Mr Trump is due in Seoul on Nov 7 as part of a swing through Asia, the White House said yesterday. The US President will also be visiting Japan and China as well as attending the Asia-Pacific Economic Cooperation summit in Danang, Vietnam, and the Asean meetings in Manila, in the Philippines, on Nov 12 and 13.
He is scheduled to kick off the trip with a visit to the US Pacific Command in Hawaii on Nov 3.