Beijing | A senior Chinese Foreign ministry official has warned of "serious measures" if Australia ups the ante in opposing Chinese seizure of islands and coral reefs in the South China Sea.
Mr Cong Peiwu, director-general of the Department of North America and Oceania in the Chinese Foreign Ministry, said Australia's position was "detrimental to the political foundation of our relationship". It was not conducive to political stability, "especially in the South China Sea".
The warning came as US Vice-President Joe Biden stood with Prime Minister Malcolm Turnbull to reaffirm the two countries' commitment to responding to "any challenges in the Pacific with a united front". 
"It's important we stand together," Mr Biden said after talks with Mr Turnbull and Foreign Minister Julie Bishop. Earlier he visited troops on the Australian warship, HMAS Adelaide, anchored in Sydney Harbour.
Mr Biden will on Wednesday wrap up a four-day visit to Australia with a policy speech about the future of US-Australia relations.
The Vice-President said he and Mr Turnbull reaffirmed their commitment to joint military training exercises and maintaining "the free flow of trade in the air and on the sea".
"They are the lifeblood lines of commerce and the economic growth worldwide," he said.
"That's why last week both our nations issued strong statements urging China and the Philippines to abide by the tribunal decision with regard to the South China Sea."
Mr Peiwu said that China would enter negotiations with the Philippines, the country that took the issue to the Permanent Court of Arbitration in The Hague, and expected there would be '"negotiation and consultation", even though he said the Philippines had "unilaterally applied to have the issue taken to the court".
China was "very unsatisfied" with the actions of countries like Australia which had raised the issue.
However, he said there was no danger to the freedom of navigation in one of the world's most important maritime routes. Mr Peiwu said more than 100,000 ships navigated the South China Sea each year, and not one had ever complained of obstruction.
Mr Turnbull announced Australia's training role in Iraq would be expanded beyond army personnel to police.
He also also touched on anxiety about passage of the Trans-Pacific Partnership before Barack Obama's presidency ended. "We know that the Biden touch will deliver the TPP and that will be very important for economic growth in our region," he said.
Mr Peiwu's comments follow the ruling from the PCA last week, which found there was "no legal basis for China to claim historic rights to resources within the sea areas falling within the 'nine-dash line".
He did not spell out specific measures that could be taken, but one obvious step would be to restrict the number of Chinese tourists visiting Australia. This is a boom area for the Australian economy, with recent figures showing that more than one million Chinese tourists visit each year.
Without referring specifically to tourism, or Chinese investment, he said "our present cooperation will also be damaged as a result" of any escalation in Australia's position, like joining US-led patrols in parts of the South China Sea which China claims exclusive domain over.
China's PLA Navy Commander, reportedly told his US counterpart, John Richardson, in a meeting in Beijing on Monday China would continue construction in the disputed area.