Mr Gilbert was nominated for the position of ambassador to New Zealand and Samoa by US president Barack Obama in October. Today's ceremony marks his acceptance of the nomination, which still needs to be confirmed before he takes up the role.
He told the Foreign Relations Senate Committee that if approved he will use his banking background to "advance our nation's interests, nurture economic ties, and build on our growing relationships".
"If confirmed, I will work to promote an even stronger economic link between our countries - capitalising on opportunities not only to increase US investment in New Zealand, but also to expand New Zealand investment here at home."
Relations between New Zealand and the United States have almost returned to normal after 25 years of reprisals by the United States in response to New Zealand's anti-nuclear position.
Mr Gilbert - who is married with two daughters - said the relationship was "stronger now than it has been in nearly three decades".
"In Wellington, we have a partner committed to expanding global trade and promoting democratic values while pursuing peace and security," he said.
"These are exactly the sort of diplomatic relationships we seek to forge around the globe, and we will continue to expand our connections to the next generation of New Zealanders of all backgrounds to renew and strengthen our partnership."
He also mentioned New Zealand's role in the United Nations, Kiwi's peacekeeping missions in Afghanistan, counter-terrorism measures in Asia, climate change research, and the 50-year Antarctic scientific partnership with the US in his speech.
"I have been fortunate to have had a diverse and interesting career in business, community engagement, and professional athletics. I am humbled to be nominated to represent the United States to countries as diverse as New Zealand and Samoa," he said.
