(CNN) -- Igor is now an Atlantic Ocean hurricane and could reach significant strength by Monday, the National Hurricane Center reported Saturday night.
With maximum sustained winds of 75 miles (120 kilometers) per hour, Igor is a Category 1 hurricane and is moving west at 17 miles (28 kilometers) per hour, the center said.
"Igor is expected to gather strength and become a dangerous Category 3 on Monday and may reach Category 4 strength on Tuesday or Wednesday," said CNN meteorologist Dave Hennen.
The storm is not forecast to threaten land for at least the next five days as its center likely moves north of the Leeward Islands and Puerto Rico, Hennen said. He added it is still too early to tell if Igor will be any threat to the United States.
At 11 p.m. Saturday, Igor, the fourth hurricane of the season, was 1,275 miles (2,050 kilometers) east of the Leeward Islands.
No watches had been posted as of Saturday night.