MIAMI: Alex strengthened into the first hurricane of the 2010 Atlantic season Tuesday, US experts said, threatening coastlines in Mexico and the United States and disrupting oil cleanup efforts in the Gulf of Mexico.

"Maximum sustained winds have increased to near 75 miles (120 kilometers) per hour, with higher gusts," the Miami-based National Hurricane Center said in a bulletin.

"Additional strengthening is forecast prior to landfall," which the NHC said is expected Wednesday night near the US-Mexico border, separating Texas and Tamaulipas states.

The Category One hurricane was tracking westward and not forecast to turn towards the massive BP oil spill along the US Gulf Coast, but its severe winds were churning up large waves that have brought a halt to clean up operations and threaten to push more of the huge slick onto the coastline.

BDST: 8:53 HRS, June 30, 2010