Seoul says N Korea sanctions may be eased before full denuclearisation

South Korea said today that sanctions against North Korea could be eased once it takes "substantive steps towards denuclearisation", seemingly setting the bar lower than Washington for such a move.

Last week's Singapore summit between US President Donald Trump and North Korean leader Kim Jong Un produced only a vague statement in which Kim "reaffirmed his firm and unwavering commitment to complete denuclearisation of the Korean Peninsula".

Amid fears the summit would weaken the international coalition against the North's nuclear programme, US Secretary of State Mike Pompeo stressed after the meeting that sanctions would remain in place until North Korea's complete denuclearisation.

But his South Korean counterpart suggested Monday they could be eased sooner.

"Our stance is that the sanctions must remain in place until North Korea takes meaningful, substantive steps towards denuclearisation," Foreign Minister Kang Kyung-wha told reporters.

Seoul and Washington shared the same "big picture" view and would continue close consultations, she added.

The comments come just days after China's foreign ministry suggested that the UN Security Council could consider easing the economic punishment of its Cold War-era ally.

Any reduction in tensions on its doorstep is welcome for China, North Korea's closest ally, which accounts for around 90 per cent of Pyongyang's trade.

The same goes for the South's dovish President Moon Jae-in, who supports engagement with North Korea and held his own summit with Kim in April.

Until recently Trump had pursued a "maximum pressure" campaign -- with both China and South Korea on board -- of tough rhetoric and tightened sanctions against Pyongyang.

But analysts say the Singapore summit has made it hard for the Trump administration to return to that policy even if its current diplomacy with North Korea proves to be a failure.

"The symbolism of the meeting ensures that the maximum pressure campaign has peaked," said Scott Snyder, senior fellow for Korea Studies at the US Council on Foreign Relations, in a commentary.

"In practice, China and South Korea will push for relaxation of economic pressure on North Korea," he added.