PARIS — France is battling a surge of COVID-19 cases in French Guiana, its South American territory that shares a border with badly hit Brazil.

The so-called “R” number, which indicates how many people will be contaminated on average by an infected person, has climbed quickly to 1.8, said Clara de Bort, who heads the territory’s regional health authority. That suggests each infected person is passing the virus on to nearly two other people.

Speaking Monday on France-Info radio, de Bort said French authorities are mulling whether to place the territory’s 300,000 people into a short lockdown again to bring the outbreak back under control. The territory’s outbreak is expected to peak in July.

“The peak still hasn’t been reached,” she said. “We fear that we’re only at the beginning of the upswing of the epidemic.”

She suggested that it’s impossible to stop the illness crossing from Brazil, saying: “The pressure from our immense neighbor and the 700 kilometers (400 miles) of frontiers that we share is necessarily huge.”