(CNN) Three Chinese warships have pulled into Australia's Sydney Harbor for a short stopover.

People's Liberation Army supply vessel, a frigate and an amphibious vessel docked at the Garden Island naval base on Monday morning, People's Liberation Army supply vessel, a frigate and an amphibious vessel docked at the Garden Island naval base on Monday morning, according to CNN affiliate 7 News.

Although the visit was not publicly announced, Australian Prime Minister Scott Morrison said plans for the stopover had been in place for "some time." The media is often invited in for an official welcome, but this time no cameras were allowed inside.

"It may have been a surprise to others but it certainly wasn't a surprise to the government," Morrison told reporters in the Solomon Islands, according to CNN affiliate SBS.

"Australian naval vessels have visited China. This was a program of a reciprocal visit. That is a further demonstration of the relationship that we have."

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