United States President Barack Obama has announced that the Pacific Rim countries have reached a preliminary agreement on free trade talks.
Mr Obama made the announcement at the APEC summit in Honolulu on Sunday.
He said the Trans-Pacific Partnership will cover much more than reducing tariffs between the member countries.
A deadline of next year has been set by the TPP countries for the deal to be completed.
However, Mr Obama acknowledged that there are plenty of difficult negotiations to come, including on barriers to agricultural trade.
Removal of export barriers may have to be phased in
New Zealand Deputy Prime Minister Bill English says the removal of barriers to exports to Pacific Rim countries may have to be phased in over a long period.
Mr English says the preliminary agreement doesn't mean tariffs on New Zealand's exports would be eliminated straight away once a deal is reached.
He says industries in some countries will find it difficult without tariff protection.
Now we've got countries who want to join knowing that it's a quality, comprehensive trade agreement - it's not been compromised to accommodate more countries. But there has to be some give and that could be around the length of time it takes to achieve elimination of trade barriers, he said.
Mr English says even countries traditionally resistant to free trade recognise it as one of the few options left to reinvigorate growth and provide jobs if the world economy falters again.
He says the agreement is an important milestone and the commitment to an early finish is a surprise.
Mr English says negotiators had been expecting a deadline for a final deal after the next presidential elections in the United States.
He says the agreement to try and conclude talks before the election in November 2012 is encouraging.
China hints at joining trade pact
China says it will consider joining negotiations for a Trans-Pacific trade agreement if it is invited.
The Trans-Pacific Partnership already includes Brunei, Chile, New Zealand and Singapore. Australia, Malaysia, the United States, Vietnam and Peru are negotiating to join.
US Secretary of State Hillary Clinton says the negotiations for other counties to join are a key priority at the APEC forum in Honolulu.
China's assistant commerce minister Yu Jianhua says the free trade deal should be inclusive, transparent and complementary to APEC's agenda.
Meanwhile, Chinese President Hu Jintao has sought to reassure executives at the APEC summit that China is open for business and will advance reforms but expects more say in setting the agenda for the global economy.
In a keynote speech, Mr Hu said the World Trade Organisation's Doha round of talks were the favoured arena for free trade.
This puts him at odds with tougher standards the United States is advancing through the Trans-Pacific Partnership.
President Obama announced, at the APEC summit, that the members of the trade pact had agreed to complete a deal in the next twelve months.
Mr Hu said China is committed to free trade in the region but emphasized the Doha talks should be pushed forward with the aim of offering concessions on tariffs and quotas to the least developed countries.
And he said China will work to reform the international economic system and make a more just and equitable international economic order.
The 21 members of APEC account for about 44% of global trade.