Visiting Australia with Defense Secretary James Mattis on Sunday, the US top diplomat Tillerson sought to reassure Canberra of the long-standing alliance with Washington.

With Australia close to the simmering conflict in the South China Sea, some politicians have expressed concern that the US might give concessions to Beijing in exchange for help on the North Korean threat.

"We desire productive relationships," Tillerson said after meeting his Australian counterpart Julie Bishop.

"But we cannot allow China to use its economic power to buy its way out of other problems, whether it's militarizing islands in the South China Sea or failing to put appropriate pressure on North Korea."

He also urged Beijing and other countries in the region to "step up" their efforts to resolve the North Korean crisis, which threatens the entire world.

Australia a 'beacon of hope'

The two-day visit comes as Australia and the world still reel from Washington's rejection of the Paris climate accord.

Answering a question on Trump's apparent turn to isolationism, Tillerson said that his visit "demonstrates that it certainly is not this administration's view or intention to somehow put at arm's length the important partners and allies in the world."

Mattis, also appearing at the conference alongside Tillerson and Australian Foreign Minister Julie Bishop in Sydney, called Australia "a beacon of hope" for the world.

Climate still "important" to Trump

Tillerson also commented on the climate dispute between the US and the overwhelming majority of the world nations, saying that president was "not walking away" from climate change.

"He's simply walking away from what he felt was an agreement that did not serve the American people well," he said.

The US President is interested in "perhaps a new construct of an agreement," according Tillerson, because the climate "is still important and that he wants to stay engaged on the issue."

In addition to the crisis in Asia, the two US officials also commented on the ongoing crisis in the Gulf, triggered by the decision of several Arab nations to cut ties with Qatar over its alleged support to Islamist groups and links with Iran. Tillerson called on the Gulf countries to stay united and "address these differences." He added that it was unlikely that the strife would influence the fight against Islamic terrorism.

dj/rc (AP, AFP, Reuters)