US President Barack Obama says he hopes to have an agreement on framing a vast pan-Pacific trading bloc by November.

US President Barack Obama says he hopes to have an agreement on framing a vast pan-Pacific trading block by the time he makes his next visit to Asia in November.

The Trans-Pacific Partnership (TPP) would encompass 40 per cent of the global economy and include 12 nations. Talks on setting up the pact have been delayed by intricate market access negotiations between Japan and the United States.

Obama says he and New Zealand’s Prime Minister John Key discussed the latest timeline for the deal in Oval Office talks on Friday, and that he hoped to have a “document” on it by the end of the year.

“My hope is that by the time we see each other again in November, when I travel to Asia, we have got something that we have consulted with Congress about, that the public can take a look at,” Obama said, though he warned there was a lot of work still to be done on an agreement.

Obama is due to travel to the Asia Pacific Economic Cooperation (APEC) summit in Beijing, the East Asia summit in Myanmar and the G20 summit in Brisbane, Australia at the end of the year.

Chief negotiators from countries set to join the TPP are due to meet again in July.

In the last talks in Singapore in May, trade ministers agreed on an intensified timetable for talks, but could not say when a final deal might be concluded.

The negotiations have been slowed while the United States and Tokyo debate key details, including Japanese tariffs on agricultural imports and US access to Japan’s auto market.

Together, the two countries make up 80 per cent of the total GDP of the prospective free trade area.

Outside the United States, there are concerns Obama may struggle to win congressional backing for the deal – especially in a year in which lawmakers are facing mid-term elections in which free trade is always a divisive issue.

That is one reason why Obama rarely mentions the TPP without touting it as a significant job creating opportunity for the US economy at a time of still-high unemployment.

The 12 prospective TPP members are Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, the United States and Vietnam.