Chinese President Xi Jinping said that China will continue to open up its economy amid the rising protectionism around the world that has led to a slowdown in world trade.
Speaking at the Asia-Pacific Economic Cooperation (Apec) CEO Summit on Saturday, he urged economies in the region to persist in building the Free Trade Area of the Asia-Pacific (FTAAP), that aims to link Pacific Rim economies from China to Chile.
He added that China was committed to concluding negotiations for the Regional Comprehensive Economic Partnership (RCEP), seen as a rival to the United States-backed Trans-Pacific Partnership (TPP) that was dealt a blow after businessman Donald Trump was elected US President on an anti-trade platform about two weeks ago.
"China's door will never be shut, and will only be opened wider," he told business leaders in his keynote address at the Apec CEO Summit.
The TPP and the RCEP are seen as possible pathways towards eventually realising the broader FTAAP.
But with uncertainty surrounding the TPP's fate, the Asean-led RCEP is now widely seen as the only viable pathway to the FTAAP.
Seven TPP countries are included in the RCEP, which involves all 10 Asean members plus Australia, New Zealand, China, Japan, South Korea and India.
At a separate Apec CEO Summit panel on Saturday, New Zealand Prime Minister John Key had said the TPP was part of the Obama administration's Asia pivot to refocus the US' resources and project its leadership in the region.
Asked if the world will turn towards China for economic leadership if the TPP falls through, he said: "If the US is not there, that void has to be filled, and it will be filled by China."
Australian Prime Minister Malcolm Turnbull, commenting on the RCEP separately, had told reporters that it is not as far-reaching as the TPP, but "the more access we can get to more markets for our exports, the better".
Both trade pacts aim to cut tariff and non-tariff barriers, but the RCEP calls for lower and more limited rules and standards.
US President Barack Obama - in championing the TPP - had argued that if the US did not take the lead in setting trade rules, it would allow other countries to set standards that are not as stringent.
The TPP can come into force only if it is approved by six countries that account for at least 85 per cent of the group's economic output.
This means that ratification by both the US and Japan, as the world's No. 1 and No. 3 economy respectively, is essential.
But ratification in the US is unlikely with Mr Trump's election win.
But leaders of the 12 TPP member countries pledged at a meeting on Saturday that they would push ahead with getting approval of the deal in their home countries.
Mexican President Enrique Pena Nieto, speaking at an Apec CEO Summit forum before the meeting, said that his country's geopolitical situation meant that the US will always be its closest partner.
"Our eyes will always be set towards North America," he said.
Separately, a spokesman for Japanese Prime Minister Shinzo Abe told a press conference that the TPP remains the "role model" of a "high-quality, 21st-century type of agreement".
"So first of all, we have to fulfil our commitment for the passage and approval of the TPP.
"Then it will have a positive influence over the RCEP negotiations.
"That is the right order we have to follow," said Mr Yasuhisa Kawamura.
Meanwhile, Mr Xi and Mr Obama also met, and Mr Xi spoke highly of Mr Obama's efforts to develop bilateral ties, China's Xinhua news agency reported.
Mr Xi also said he had a phone conversation with Mr Trump, and added he was willing to work with Mr Trump to expand cooperation.
Mr Obama said he and Mr Xi had established a candid, friendly and constructive relationship and enhanced mutual trust, Xinhua said.
Mr Obama also told Mr Xi that he had underlined the importance of US-China relations to Mr Trump, and stressed that there should be a smooth transition of bilateral ties.
