MIAMI -- Tropical Storm Seymour is getting stronger in the Pacific off Mexico's coast and is expected to become a hurricane.

The storm's maximum sustained winds early Monday have increased to near 65 mph (105 kph). The U.S. National Hurricane Center says additional strengthening is expected and Seymour is forecast to become a hurricane later in the day and could become a major hurricane by late Tuesday.

The storm is centred about 395 miles (636 kilometres) southwest of Manzanillo, Mexico, and is moving west-northwest near 15 mph (24 kph).

The storm is not currently a threat to any land.