Prime Minister John Key flies out to Cambodia this morning for the annual East Asia Summit.
Key will join leaders from 10 Asean countries for talks covering regional political, security and economic issues.
He will meet Cambodia's president in Phnom Penh and also meet opposition leader and Nobel Peace Prize winner Aung San Suu Kyi.
Key will then visit neighbouring Burma, making him the first New Zealand prime minister to do so.
He will have the opportunity to congratulate US President Barack Obama on his re-election during the Trans Pacific Partnership talks.
Obama denied his trip to Burma was an endorsement of the government there, calling it an acknowledgement of the progress made in shaking off decades of military rule and encouragement for it to go further.
Obama gets 'hands dirty'
On Monday, Obama will become the first serving US president to visit Burma, also called Myanmar.
Some human rights groups object to the visit, saying Obama is rewarding the country's quasi-civilian government before democratic reforms are complete. But he told a news conference in Thailand he knew there was much still to do.
"I don't think anybody is under the illusion that Burma's arrived, that they're where they need to be," he said.
"On the other hand, if we waited to engage until they had achieved a perfect democracy, my suspicion is we'd be waiting an awful long time," he added.
"One of the goals of this trip is to highlight the progress that has been made and give voice to the much greater progress that needs to be made in the future."
Obama will meet President Thein Sein, a former junta member who has spearheaded political and economic reforms since taking office in March 2011, and opposition leader Aung San Suu Kyi, who led the struggle against military rule and, like Obama, is a Nobel Peace Prize laureate. She is now a lawmaker.
"I'm not somebody who thinks that the United States should stand on the sidelines and not want to get its hands dirty when there's an opportunity for us to encourage the better impulses inside a country," Obama said.
"And, in part, I'm taking my guidance from what Aung San Suu Kyi, who I think knows quite a bit about repression in Burma, sees as the best means to continue the development and progress that's being made there."
White House officials have said Obama would press Burma's leaders to restore calm to the western part of their country and bring instigators of ethnic violence there to justice.
After a recent meeting with senior Obama aides, rights activists left satisfied that Obama wanted to push hard on human rights and political and economic reform in closed-door talks with Thein Sein and in his public remarks, including a speech.
After Burma, Obama will attend an East Asia Summit in Cambodia as he seeks to recalibrate US economic and security commitments to counter China's influence at a time when America is disentangling itself from wars in Iraq and Afghanistan.
But his attention will be divided during his travels as he faces a simmering crisis in the Gaza Strip pitting Israel against Hamas militants, plus economic problems at home.