The US Senate Foreign Relations Committee held a hearing on Friday to consider the nomination of David Huebner to become the next American ambassador to New Zealand and Samoa.
If confirmed, Mr Huebner would become the third openly gay ambassador in US history and the first to be confirmed by the Senate.
The 49-year-old lawyer is currently based in Shanghai where he handles international arbitration and mediation cases for an American law firm, Radio New Zealand's Washington correspondent reports.
Mr Huebner previously spent 10 years in Tokyo; experience the Obama administration says would qualify him to represent US interests in the Asia-Pacific region.
He is also the general counsel for the Gay and Lesbian Alliance Against Defamation and previously served on the group's board.
Before the committee hearing, Mr Huebner spoke of the enthusiasm and dedication of the US teams in New Zealand and Samoa.
"It would be my great honour to lead those inter-agency teams and to work closely with Congress and the executive branch to promote and protect, to the best of my abilities, the interests of the United States in New Zealand and Samoa.
"If confirmed, I would do my best to strengthen and expand our already strong relations with those two very good friends in the Pacific."
Mr Huebner told lawmakers at the hearing he would be honoured to represent Washington's interests in Wellington.
"Our two countries have a very similar vision in which we seek a more secure, prosperous and open global community for the 21st century. Even more importantly, we actively collaborate on moving that vision forward."
Quizzed by the committee on New Zealand's attitude to nuclear power and the visits of US nuclear-powered ships, Mr Huebner said the nuclear-free legislation is firmly embedded in the national identity.
However, he said despite the differences, the US and New Zealand have maintained a strong relationship over the past 25 years.
"New Zealand has been an extraordinary partner on issues of national security, regional security, global security, non-proliferation and anti-terrorism and related issues, even though we are operating within a framework that has certain constraints on our military relationship.
"If I'm confirmed to the position, one of my priorities would be exploring ways in which we can deepen and expand that kind of engagement."
US president Barack Obama has faced criticism from gay leaders that he is not living up to his campaign promises to ensure equal rights.
White House advisers say Mr Obama is intent on making progress on that issue and it is thought Mr Huebner's nomination would take some steps in that direction.
Mr Huebner is expected to receive the support of the Senate Foreign Relations Committee and then be approved by the full Senate.