Morrison announced his positive COVID test on Twitter, saying that he had been testing himself daily since Sunday and had been receiving negative results.

Hours before posting the tweet, Morrison posted a picture of himself shaking hands with Nauruan President Lionel Aingimea. The two had met in Sydney earlier in the day “to reinforce strong Australia-Nauru ties, resilient infrastructure, Pacific Islands Forum unity and Ukraine’s sovereignty,” Morrison said.

Neither of the leaders was wearing masks in the picture.

It was not immediately clear what level of contact Morrison and Aingimea had during the visit and the extent of the Nauruan leader’s risk of exposure. Morrison did not mention his contact with Aingimea in the Twitter thread, or speculate on when and where he may have contracted COVID.

Newsweek has reached out to the government offices of Morrison and Aingimea for further comment.

Aingimea was elected in 2019 to lead Nauru, which described itself on its website as the smallest island nation in the world with a population of just under 10,000.Sydney, where Aingimea’s meeting with Morrison took place Tuesday, is 16 hours ahead of Eastern Standard Time.

Morrison tweeted that he developed a fever late Tuesday, local time, and took another COVID test. When the results came back as inconclusive, he took a PCR test that came back positive.

The Australian prime minister tweeted that he was now experiencing “flu-like symptoms and will be recovering over the next week.”

He also said that he is currently isolating at home and is “continuing to follow health guidelines.” His wife Jenny Morrison and their two daughters have all tested negative for the virus, but will still “isolate for seven days at home as close contacts,” Morrison tweeted.

He added that he will continue to fulfill duties as prime minister virtually, including virtually chairing meetings of Australia’s National Security and Expenditure Review Committees.

“I will also be focused on our urgent response to the tragedy unfolding in Ukraine and Russia’s senseless aggression, staying in regular contact with our security and intelligence officials & our international partners, as well as working with the Treasurer to finalize the Budget,” Morrison tweeted.

Nauru keeps a relatively low profile in the public sphere and has not posted anything on its Twitter page since September 2020. Aingimea does not appear to be active on social media either.

Update 3/1/2022, 12:45 p.m. ET: This story has been updated with additional information.