Australian politician Barnaby Joyce, who has dual New Zealand citizenship, has accused Jacinda Ardern of "climate hypocrisy" over New Zealand's emission targets.
When speaking about the pressures of climate change with Australian Prime Minister Scott Morrison, she made pointed comments that Australia would have to "answer to" the rest of the Pacific.
However, the New Zealand Prime Minister has been criticised as she is set to use 27.7 million tonnes of credits from a successful 2012 target to reach New Zealand's 2020 Kyoto target.
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Carry-over credits are a carbon accounting measure used by countries to count old emission reductions that exceeded previous international goals towards current targets.
"We don't need to be lectured about our environmental policy when we are complying with our agreements," Joyce told The Australian.
"When New Zealand starts quoting environmental policy, start counting your carbon credits."
"They should listen closely to me because I nearly won New Zealander of the year."
Liberal MP Jason Falinski also slammed the New Zealand Government for showing a "lack of consistency and standards".
"At the moment, no one wants to hold people accountable when they didn't meet their targets so we introduced carry-over credits," he told The Australian.
"There is actually a rational reason for applying carry-over credits: to encourage people to exceed their targets when they can and not reward people who don't meet their targets.
The Morrison Government has not ruled out using carry-over credits from Kyoto to meet its Paris climate targets.
New Zealand called for Australia to back a UN commitment to a carbon-neutral economy by 2050 during last August's Pacific Islands Forum.
Under the 2015 Paris Agreement, designed to keep global warming well below 2C, New Zealand pledged to reduce its emissions 30 per cent by 2030 on 2005 levels.
Last week, Green party co-leader and Climate Change Minister James Shaw said that the use of Kyoto carryover credits to meet Paris climate targets is an "allergic reaction".