The United Nations is using a meeting of world leaders in the US to emphasise how important it is for countries to pull their weight on emissions reductions.

Acting Prime Minister Barnaby Joyce argues Australia must ensure it can support its economy first and foremost to be "a good ally".

"I'm sure that those within the American administration clearly understand that a weak Australia is a no-use Australia," he told Sky News on Thursday.

"To be a strong Australia we have to have a strong economy, we have to earn the export dollars, we have to be able to support ourselves."

Pressure is building on the Nationals to agree to more ambitious climate targets ahead of COP26 talks in Glasgow in November.

"We've met every agreement that we've made. Other countries have not. I'm not saying America hasn't. But other countries have not," Mr Joyce said.

Australia is yet to update its 2015 commitment to cut emissions between 26 and 28 per cent on 2005 levels by 2030.

Prime Minister Scott Morrison, currently in the US, aims to update this target by COP26 but the Liberal leader will need support from the Nationals.

Climate was on the agenda when Mr Morrison met with US House speaker Nancy Pelosi.

US President Joe Biden brought climate envoy John Kerry to his meeting with Mr Morrison.

UK Prime Minister Boris Johnston has urged the world to "grow up" and stop trashing the planet, while China says it will not build new coal-fire power plants overseas.

Australian coal exports have been one of the casualties from increasingly strained diplomatic ties with China.

Labor's foreign affairs spokeswoman Penny Wong warns the government's failure to commit to net zero by 2050 risks leaving Australia behind and undermining its relationship with the US.

"It diminishes us in the region, thus hobbling our ability to add value to the alliance as a partner of choice for our neighbours," she told the United States Studies Centre.

Australian Associated Press