The top United States military chief for the Pacific region has visited New Zealand against a backdrop of rising geopolitical tensions with China increasingly asserting its might.

US Admiral John Aquilino arrived in Wellington on Saturday after visiting Australia with a much larger contingent, including top general Mark Milley who there warned China was "noticeably and statistically more aggressive" and seeking to "bully and dominate".

Aquilino himself used similar language in addressing the Shangri-La Dialogue security conference in Singapore in June, saying it was "potentially the most dangerous period" in the Pacific since World War II, and pointed to Beijing's "destabilising" and "coercive" actions.

Speaking to media in Wellington on Monday, however, he was much softer in his rhetoric only stressing the need to "work peacefully together", perhaps acknowledging the heightened political sensitivities here, particularly around trade with China.

Admiral John Aquilino, commander of US Indo-Pacific Command. Photo / Mark Mitchell

Aquilino, accompanied by his wife Laura, placed a wreath at Pukeahu National War Memorial Park.

Asked directly about the recent US push into the region, announced at the Pacific Islands Forum in Fiji last month, Aquilino pushed back at any suggestion it was to counter China's recent initiatives, including a security agreement with Solomon Islands and an unsuccessful attempt at a much broader deal.

"The timing was the timing," said Aquilino, who is responsible for 380,000 military personnel across the Indo-Pacific region.

"The fact that the Vice President of the United States has articulated our commitment to the South Pacific Islands is the important issue.

"The leadership that New Zealand and Australia shows in the South Pacific region is critically important, and it helps us deliver the capabilities and things the South Pacific islands need and want."

Aquilino also spoke of the more impending security threat of climate change impact facing low-lying Pacific island countries.

The US military aims for net zero emissions by 2050 but with a carbon footprint greater than some 140 countries critics say it needs radical change.

If the US military were a country, its fuel usage alone would make it the 47th largest emitter of greenhouse gases in the world, sitting between Peru and Portugal.

Asked directly about this contradiction, Aquilino deferred, simply acknowledging the topic was "important to all the nations in the region".

Admiral John Aquilino and his wife Laura laying a wreath at the Tomb of the Unknown Warrior at Pukeahu National War Memorial Park in Wellington. Photo / Mark Mitchell

"If it's important to the South Pacific islands, it's important to both the United States and I'd let Air Marshal Short articulate, but I believe he's also expressed the importance to New Zealand as well."

Aquilino's visit comes in the year marking 80 years since US marines arrived here before embarking for the Pacific in World War II.

US Admiral John Aquilino, commander of US Indo-Pacific Command, inspecting the Tri-Services honour guard during his visit. Photo / Mark Mitchell

Aquilino said the relationship with New Zealand "runs deep and long" and he saw it "only getting stronger".

"We value our partnerships each and every day, no matter how big or small.

"The United States has been a Pacific nation our entire life. We will continue to operate in the Pacific ... we will operate in the areas that international law allows to preserve the peace, prosperity, and expansive relationships in the Pacific."