HOUSTON, July 13 (Xinhua) -- Tropical storm Barry became a hurricane as it was making its final approach toward the Gulf Coast onto the southern U.S. state of Louisiana on Saturday morning, according to the U.S. National Hurricane Center.

Barry's maximum sustained winds on Saturday morning reached 75 miles per hour (about 120 km per hour), strengthening as Category 1 hurricane.

If Barry maintains the current track, it is expected to make landfall on Marsh Island, about 160 km west of New Orleans, a Louisiana city on the Mississippi River and near the Gulf of Mexico.

Barry will also bring dangerous storm surge and heavy rains across the north-central Gulf Coast following its landfall. Residents in the affected regions who had not been put under voluntary or mandatory evacuation were told to take shelter.

Local governments and residents have geared up for the hurricane. New Orleans and Baton Rouge, the capital city of Louisiana, are among the cities at high risk of flooding. Mississippi River is forecast to crest at 19 feet (about 5.8 meters) in New Orleans on Saturday.

In New Orleans, voluntary evacuations have been issued for areas which are not protected by levees.

Both U.S. states of Louisiana and Mississippi have declared state of emergency in advance of Barry's arrival.

At a press conference on Friday, Governor of Louisiana John Bel Edwards said the state was ready for the impact from the country's first tropical system this year, and levees in New Orleans should withstand the floodwaters.

Meanwhile, U.S. National Guard has mobilized up to 3,000 troops in Louisiana for the upcoming hurricane.