South Korea, US agree to pressure North Korea, China hopes for North-South talks

South Korean President Moon Jae-in and his US counterpart, Donald Trump, agreed to apply maximum pressure and sanctions on North Korea in a telephone call on Monday, while China expressed hope that North and South Korea could resume contact soon.

However, North Korea has called an offer of talks from the South "insincere", in a rare meeting of high-level officials.

South Korean foreign minister Kang Kyung-wha spoke to her North Korean counterpart Ri Yong Ho on Sunday on the sidelines of a forum in Manila.

Tensions have escalated on the Korean peninsula in recent months amid repeated missile tests by the North.

US Secretary of State Rex Tillerson on Monday ruled out a quick return to dialogue with North Korea, as he said new UN sanctions showed the world had run out of patience with Pyongyang's nuclear weapons ambitions.

The UN Security Council voted on Saturday to impose fresh sanctions against North Korea over its missile programme. A resolution banning North Korean exports and limiting investments in the country was passed unanimously. The sanctions could slash North Korea's $3 billion annual export revenue by a third.

The US-drafted resolution bans North Korean exports of coal, iron, iron ore, lead, lead ore and seafood following Pyongyang's two intercontinental ballistic missile tests in July.

It also prohibits countries from increasing the current numbers of North Korean labourers working abroad, bans new joint ventures with North Korea and any new investment in current joint ventures.

Speaking to reporters at a security forum in the Philippine capital, Tillerson said Washington would only consider talks if Pyongyang halted its ballistic missile programme - something the North has insisted it has no intention of doing.

"The best signal that North Korea could send that they're prepared to talk would be to stop these missile launches," Tillerson said.

During the hour-long phone call, Moon and Trump said they would continue cooperating to rein in North Korea, particularly ahead of a regular joint military drill set for late August, South Korean presidential office spokesman Park Su-hyun told a media briefing.

Moon was also cited as saying there was a need to show North Korea the door to dialogue is still open, should Pyongyang give up its nuclear program.

In a separate statement, the White House said the two leaders "affirmed that North Korea poses a grave and growing direct threat to the United States, South Korea, and Japan, as well as to most countries around the world".

"The leaders committed to fully implement all relevant resolutions and to urge the international community to do so as well," the White House said.