The deadly H5N1 bird flu strain has arrived on the Australian mainland with test results confirming a bird found on the Western Australian coast was positive for the disease.

The agriculture minister, Julie Collins, confirmed a brown skua found unwell last Sunday at Cape Le Grand national park in southern WA died from H5N1.

Tests taken in WA suggested a sick giant petrel found in the same area was also infected.

Collins said samples from the petrel were being sent to the CSIRO’s laboratory for confirmation.

The highly pathogenic strain has killed millions of birds globally and crossed over into mammal species including elephant seals.

Collins promised a nationally coordinated response that would initially focus on the extent to which the disease may have spread in wildlife.

She said there was no evidence of mass mortalities so far or of infection of any poultry.

Anthony Albanese said earlier on Saturday the arrival of H5N1 bird flu was “concerning” but the government had spent $113m in preparation and was focused on trying to limit its spread.

“What we’re about is making sure, firstly, that we do whatever we can to restrict the spread,” the prime minister said.

“We, of course, always examine these issues carefully. We have prepared for it.

“This is something that has happened through migratory birds. It’s happened, by definition, around the world, and that is why we’ve been preparing for this.”

More details soon …