Scott Morrison says he would act if he believed there was a weakening in the coal export market, after imports have reportedly been banned at a Chinese port.
The prime minister insists a ban on Australian coal exports entering China is just an issue of local rules and not a wider problem between the two countries.
There are fears the action by Chinese customs officials at the northern port of Dalian could be part of retaliation by the Asian giant over the coalition's stance on telecoms group Huawei.
But Scott Morrison says he hasn't seen any evidence to suggest it relates to tensions, while Trade Minister Simon Birmingham said it appears the ban applies to all countries and is not targetted at Australia.
"I think people should be careful about leaping to conclusions about this," Mr Morrison told reporters in Auckland, where he met the New Zealand prime minister on Friday.
"This is not the first time that on occasion, local ports make decisions about these matters.
"We will, of course, continue to engage with those local ports and those authorities and work through the same regulatory issues that we have worked through in the past."
The northern port of Dalian has enacted the ban and will also cap overall coal imports from all sources for 2019 at 12 million tonnes.
BHP said earlier in the week delays for coal importers unloading across China had more than doubled to about 40 days, but that all suppliers were facing the same issue.
Senator Birmingham on Thursday night asked Australia's ambassador in Beijing, Jan Adams, to seek clarification from the Chinese government.
He says he doesn't believe there is a ban on coal exports into China, with the issue related instead to import restrictions and quotas.
"We are confident that the measures being put in place are not discriminatory to Australia," he said on Friday.
The minister stressed that when Australian coal imports to China have experienced lags in the past, the pace has later picked up quickly.
In 2018, Australia exported 89 million tonnes of coal to China, worth $15 billion, just shy of a quarter of the country's total coal exports.
The Dalian port received seven million tonnes of that.
Mr Morrison said he "certainly wouldn't think it was wonderful" if there was any weakening in that market.
"It would have a very serious impact on the Australian economy, and I would be concerned about it, and I would act upon it," he said.
The Australian dollar fell overnight after reports of a ban broke, but rallied on Friday morning in the face of reassuring comments from ministers.
China foreign ministry spokesman Geng Shuang said customs officers were continually inspecting and testing imports for safety and quality "to safeguard importer rights and interests and protect the environment".
Beijing has been trying to restrict imports of coal more generally to support domestic prices.