Powerful Hurricane Matthew continued to move slowly Monday toward Jamaica and Haiti, and weather forecasters said it could deliver a major strike to the two countries, according to dpa. The US National Hurricane Centre said that "life-threatening" rain, wind and storm surge was expected in Haiti Monday night. Warnings and watches were in effect across parts of the Caribbean as the Category 4 storm made its way toward land. Five provinces of Cuba, including Guantanamo and Santiago de Cuba, as well as parts of south-eastern and central Bahamas were under a hurricane warning. Matthew was about 360 kilometres south-west of Port-au-Prince, Haiti, as of 5 pm Monday (2100 GMT), with maximum sustained winds of 220 kilometres per hour (kph) and moving at 11 kph. As much as 100 centimetres of rain could be dumped on parts of Haiti, the poorest country in the Americas, and where 80 per cent of the population lives in poverty. Matthew is expected to approach south-western Haiti Monday night, pass over eastern Cuba Tuesday, and then continue toward the Bahamas late Tuesday on Wednesday. "Some fluctuations in intensity are possible during the next couple of days, but Matthew is expected to remain a powerful hurricane through Wednesday," the NHC said. Ahead of Matthew's arrival, Cuban authorities evacuated about 1 million people from coastal regions, the government said on Sunday. The US Navy ordered the evacuation of about 700 non-essential staff from its base at Guantanamo Bay, Cuba, the Pentagon said Monday. The US has sent disaster response teams to Jamaica and Haiti, and also prepositioned disaster supplies as the storm approaches landfall, according to the White House. "There should be a lot of people saying a lot of prayers for people in the Caribbean right now," White House spokesman Josh Earnest said. The storm is the second major hurricane of the season after Gaston in August. Matthew strengthened to a rare Category 5 storm on Saturday before being downgraded. It caused minimal damage to Colombia and Venezuela last week.