Matthew strengthened to a Category 4 major hurricane in the Caribbean Friday afternoon and remains a dangerous threat to Jamaica, Haiti, Cuba and the Bahamas over the next few days. The storm could still impact the U.S. East Coast by next week after its rampage through the Caribbean.

As of 5 p.m. ET, Matthew had maximum-sustained winds of 140 mph, according to the National Hurricane Center. It was moving to the west-southwest at 9 mph and was located 465 miles southeast of Kingston, Jamaica.

A hurricane watch is in effect for Jamaica and a tropical storm watch has been issued for portions of Haiti.

A hurricane is classified as "major" when its sustained winds reach 111 mph. A major hurricane is a Category 3, 4 or 5 on the Saffir-Simpson Hurricane Wind Scale. It's the first major hurricane in September in the Caribbean since Felix in 2007.

Sometime on Saturday or early Sunday, Matthew should make its long-anticipated northwest or northward turn in the Caribbean Sea, weather.com reported.

In Jamaica, Prime Minister Andrew Holness said government services have been placed on high alert, according to the Jamaica Observer newspaper. Thursday, fishermen on Jamaica’s cays and banks were advised to evacuate immediately and return to the mainland.

Other small craft operators in the island’s coastal waters were also told to return to port, while those in port were advised not to venture out, the newspaper reported.

Whether or not impacts will be indirect from a hurricane at sea or direct from a landfall in the U.S. are still unclear, AccuWeather said.

"It is too soon to rule out possible hurricane impacts from Matthew in Florida," according to the hurricane center.

© Paco Nunez/Anadolu Agency/Getty Images Flooded area is seen after the Matthew hurricane in Salina, Curacao, on Thursday. Even if Matthew turns toward the sea next week, rough surf and heavy seas would occur along the Atlantic coast.

Hurricane Matthew is the 5th hurricane and 2nd major hurricane of the 2016 Atlantic hurricane season. It's now the only hurricane or typhoon on the planet.