Scott Morrison has raised doubts about when his government will develop an emissions reduction strategy for 2050, even though he joined the Pacific Islands Forum in a statement that he will work to develop one next year.
The Australian prime minister is also trying to avoid the problem at home due to his decision to report in a speech in Chicago that China was to be treated as an economy developed in global trade and climate change negotiations, which means that Beijing should have made a significant commitment to reducing emissions.
With the UN climate action summit underway in New York, where attention is focused on strategies to achieve zero net emissions by 2050, Morrison took a step forward when his government could implement policies to achieve this goal.
"I am engaged in what I took for the Australian people and it was 26% [emission reduction] by 2030," the prime minister said. "This is what we will achieve, this is what I promised we would do, this is what I told the Australian people we would do."
Asked what the plan was beyond 2030, Morrison said: "We are making our commitments for 2030, that's what we are doing. We continue to set goals and continue to reach them."
When he was told that Australia had agreed at the Pacific Islands Forum to develop a strategy for 2050 in 2020, Morrison said "We said we would consider that as part of the release".
Sign up to receive the best Guardian Australia stories every morning
The PIF press release states that all parts of the Paris agreement "would formulate and communicate medium-term medium-term greenhouse gas emission development strategies by 2020".
"This may include commitments and strategies to achieve net zero carbon by 2050," he said. Australia signed the lack of ambition for climate policies and a discussion on coal after the conflict with the Pacific nations.
Morrison decided not to participate in the UN climate summit, instead deploying his foreign minister, Marise Payne. Even the president of the United States, Donald Trump, should have stopped the event, but stopped at the last minute, telling reporters he was interested in clean air and clean water.
Asked in Chicago why he was not at the top of the climate with other world leaders, Morrison said he had the opportunity to "talk through a different channel". The prime minister gave a major foreign policy speech at the Chicago Institute for Global Affairs Monday morning.
The prime minister said he would address his government's practical approach to environmental challenges beyond climate change when he addressed the United Nations later this week. "Wednesday, when I will deliver the national declaration at the UN General Assembly, I will focus a lot on Australia's response to global environmental challenges, which is not just about climate change, as I said today, about plastic, it's about the oceans, it's about recycling ".
In his speech on foreign policy in Chicago, Morrison reported that he wanted to redraw the conventions of global climate negotiations by treating China as a "newly developed" economy rather than a developing one – a fundamental change that would require of China to reduce greenhouse gas emissions like the developed world.
Australia wants to gain support among other nations for this putative change. But before the New York summit, China categorically rejected Morrison's argument that it had to do more to reduce emissions, pointing to the long-standing principle of the United Nations Framework Convention on Climate Change of "common but differentiated responsibilities".
China also reported that it wanted continued support from developed countries to help it manage the transition. "In particular, developed countries should implement and strengthen their commitments in providing financial and technological assistance to developing countries, opening markets and implementing practical technological cooperation".
When asked in Chicago if the language of the speech meant that Australia was now abandoning the long standing position that parties to global emission reduction agreements made various commitments at different stages of economic development, Morrison said that it was "common sense" that all countries took responsibility, in particular an emerging global power and a strong polluter like China.
Morrison said that China has become one of the leading global players and the time has come to apply similar rules to countries with similar capabilities.
"If you look at emission projections until 2030 what you will see is that Australia is meeting its commitments, you will see the United States, which is not even a signatory to the Paris agreement, is planning, but the emissions "Increases are happening in many of those countries, including China," Morrison said.
"If the goal is to reduce emissions, it is necessary to focus on the places that have the highest emissions. It seems like a good sense. All nations must take responsibility."
The Labor leader, Anthony Albanese, blew up Morrison for wiring the shift during his American visit. "I'm not sure it's constructive for Scott Morrison to send a message to China from the United States," Albanian told ABC. "We must be very measured in our comments."
Albanian said that it is legitimate for China to aspire to lift its population out of poverty. He said that "quite clearly" China remained an developing economy. He said there were pockets of prosperity around the cities and coasts in China, but "it is still an emerging economy".
The Labor leader said that China's continuing evolution would require the examination of global rules for trade and climate change, but it is better not to announce a change with a "strong hailer" and it is better to announce any move, given the conflict between Beijing and Washington, from home rather than abroad.
"I think the prime minister could have chosen more wisely where to present this topic. It is not an argument that I have heard advancing before and it is reasonable, I think, to consider why there is a change in the position of Australia. "