"We keep on raising flags and complaining about it, but they keep on sending them," said President Surangel Whipps Jr, the pro-US leader re-elected this week.
"They continually don't respect our sovereignty and our boundaries and just continue to do these activities," he told AFP from Palau's commercial centre Koror.
The most recent foray was detected earlier this week, one day after claiming victory in presidential elections.
"Once again, Chinese vessels are in our exclusive economic zone uninvited."
In what appeared to be another deliberate prod, Chinese officials earlier this year bestowed new names on two underwater mountains already claimed by Palau, Whipps added.
"They're now naming some of our seamounts Chinese names. Why? Why would you do that?"
A nation of some 20,000 people, Palau is one of the few countries to recognise Taiwan's claim to statehood.
It is a stance that has angered China, which in recent years has persuaded a clutch of new Pacific friends to walk away from Taiwan in favour of Beijing.
[...]