Trump said he is deeply concerned about the situation on the Korean Peninsula. Emphasising that China has a crucial role in resolving the crisis, he said he wants to communicate more closely with Beijing to find a solution as soon as possible.

On Wednesday evening, Trump also spoke with Australian Prime Minister Malcolm Turnbull and British Prime Minister Theresa May by phone to discuss North Korea issues, according to the White House.

Trump reiterated with the two leaders his earlier statement that now is not the time to talk with North Korea, and made clear that “all options remain open”, including “using all available diplomatic and military capabilities”, to defend the US and its allies against North Korean aggression, the White House said.

Trump’s defence secretary Jim Mattis also assured his South Korean counterpart on Tuesday via phone that any North Korean threat to US allies would be met with a “massive, effective and overwhelming” military response, the Pentagon said on Wednesday.

Meanwhile, North Korea has threatened to send “more gift packages” to the US, euphemistically referring to its nuclear arsenal.

Han Tae Song, Pyongyang’s ambassador to the United Nations in Geneva, on Tuesday said North Korea’s missile and nuclear tests, including the latest underground test of what it claimed was a hydrogen bomb, “are a gift package addressed to none other than the US.

“The US will receive more gift packages from my country as long as it relies on reckless provocations and futile attempts to put pressure on the DPRK,” the diplomat added at a UN-sponsored conference on disarmament.

Watch: US accuses North Korea of ‘begging for war’

A North Korea foreign ministry spokesman also blasted the US for leading the push for the international adoption of fresh sanctions after the underground nuclear test, South Korea’s Yonhap News agency reported.

“In the face of the US scheme of putting pressure through sanctions, we’ll respond in our own ways,” the spokesman said. “And the US will be fully responsible for the catastrophic consequences that follow.”

New sanctions apparently sought by the US and South Korea include cutting off oil supplies to Pyongyang.

The US wants the UN Security Council to impose an oil embargo on North Korea, ban the country’s exports of textiles and the hiring of North Korean labourers abroad and subject leader Kim Jong-un to an asset freeze and travel ban, according to a draft resolution seen by Reuters on Wednesday.

Yonhap also reported that South Korean President Moon Jae-in sought Russia’s support for an embargo on oil shipments to North Korea during his meeting with Russian President Vladimir Putin on Wednesday, saying a cut in oil supplies was inevitable.

At the UN Security Council, the US could have to contend with China’s and Russia’s power to veto a proposed oil cut-off. The Chinese delegation to the UN could not be immediately reached for comment.

Xinhua reported that China and Russia agreed to “keep close communication and coordination” to deal with the Korean Peninsula predicament during an emerging markets summit over the weekend in the southeast coast city of Xiamen.

Putin told reporters at the summit that he opposed levelling more “useless and ineffective” sanctions against North Koreans. “They’ll eat grass, but they won’t abandon their programme unless they feel secure,” Putin was quoted by Bloomberg.

China also demanded on Wednesday the “immediate” halting of the deployment of a US missile defence system in South Korea. Washington and Seoul have pushed for the swift application of the Terminal High Altitude Area Defence system, better known as THAAD, to deter the North’s missile threat.

Chinese Foreign Ministry spokesman Geng Shuang said at a regular news briefing in Beijing: “China demands that the US and the ROK [South Korea] respect the security interests and concerns of China and other regional countries, with an immediate stop to the deployment process and removal of the equipment.”

THAAD gives South Korea the ability to intercept and destroy short- and medium-range ballistic missiles inside or outside the atmosphere during their final phase of flight, according to the Pentagon’s Missile Defence Agency.

China has strongly and consistently opposed THAAD deployment, worrying it “poses serious threats to China’s strategic security”, Cui Tiankai, China’s ambassador to the US in Washington, said in late July.

The deployment of THAAD also faces resistance to some extent in South Korea. South Korea’s defence ministry announced on Monday that it is ready to complete the deployment by installing four more THAAD launchers, Yonhap reported.

A THAAD battery is known to require at least six rocket launchers, also involving a fire control and communications unit. Two truck-mounted launchers and a powerful X-band radar are in operation at the THAAD base in Seongju, about 300km south of Seoul.

Yonhap reported on early Thursday morning that about 400 South Korean protesters clashed with police who tried to clear the way for the deployment of the four additional THAAD rocket launchers.

Local residents have protested out of fear their town may turn into a primary target for North Korean attacks. They also worry that electromagnetic waves emanating from the cutting-edge radar could cause health and environmental problems.

With police removing hundreds of protesters from the site, the additional THAAD launchers were expected to be deployed by Thursday, Yonhap reported.