Mr Key arrived in the Thai seaside resort of Hua Hin to attend this weekend's East Asia Summit which brings together the 10 southeast Asian nations under the Asean (Association of South East Asian Nations) banner and six others -- China, Japan, India, Australia, South Korea and New Zealand.
On the agenda is a push by some countries to create a pan-Asia trading bloc to rival and eventually eclipse the European Union.
Mr Key said there was no way such a deal could be done quickly, but the fact that half of the world's trade would be represented at the table meant positive steps could be taken.
New Zealand has a trade deal with Asean, while Asean has deals in place with others at the summit.
It is estimated that tariff elimination and the reduction of other trade barriers in Cepea (Comprehensive Economic Partnership in East Asia) would lift New Zealand's GDP by $500 million or 2 percent.
Japan has even been talking about a common Asian currency, but Mr Key said that was not realistic in the short term and was probably more of a sign of an appetite for broader progress on more mundane but important issues such as trade barriers on economic issues.
Asian countries have been stung by the world-wide recession and are rethinking their strategy to boost economic growth through increasing exports to developed nations and are looking to build regional markets.
It is Thailand's third attempt to host the summit and more than 18,000 soldiers and police are being deployed at Hua Hin, south of Bangkok, to ensure the event is not disrupted.
Thailand's Government and army were embarrassed when protests disrupted the last attempt to host the summit in April.
Security forces seemed unable or unwilling to stop opponents of the current Thai Government from smashing their way into venue and forcing many Asian leaders to be airlifted out of the area.
Mr Key did not even get out of Bangkok airport and said it was very pleasing that he was able to make it to Thailand.
Bangkok is also heavily secured and the army is pledging to enforce newly enacted security regulations which essentially ban protests and create curfews in the area of the summit.
Mr Key and other leaders are heavily protected, with naval ships patrolling the beaches and military helicopters in the sky.
After attending the summit over the weekend, Mr Key travels to Malaysia for the signing of a trade deal with that country and then on to Japan for talks with the new government there and to attend a series of business and tourism promotions.
He returns to New Zealand on November 2 after attending the Bledisloe Cup rugby match against Australia, which is being played in Tokyo.
