NEW ORLEANS — BP's mounting costs for capping and cleaning up the Gulf of Mexico spill have reached $2.65 billion, it said today, but the oil giant denied reports out of Russia that CEO Tony Hayward is resigning.

The company's expenses climbed $100 million per day during the weekend, according to an SEC filing today, as engineers eyed a tropical storm headed for the Texas-Mexico border. It was expected to miss the oil spill area but could still generate disruptive waves and winds.

It was a rocky start to the week after BP stock fell 6 percent Friday in New York to a 14-year low. BP has lost more than $100 billion in market value since the deep-water drilling platform it was operating blew up April 20, killing 11 workers and starting the massive leak that has fouled the coastline in four states.