A top White House official said President Trump could sign a $15.4 billion disaster relief bill Friday and said Trump would sign it as soon as it reaches his desk.

"We anticipate, honestly, this is a real time event," White House homeland security adviser Tom Bossert said during Friday's White House press briefing. "The bill may be on its way up here right now. It requires signature by the speaker, signature by the Senate leadership or the vice president, and then signature by the president of the United States. I think that will happen today, but we soon as we get it, the president will take that seriously."

The House on Friday morning passed the disaster relief bill, which is coupled with a three-month suspension of the debt ceiling, as well as a three-month extension of government funding. The bill passed the Senate on Thursday.

Bossert thanked House and Senate leaders for coming together and passing the aid package so soon after Hurricane Harvey devastated parts of southeastern Texas, and as Florida braces for Hurricane Irma.

"They came in in a fast way to give us the emergency supplemental funding," he said. "First, FEMA still has the money that they need so there's no break in operations. … But there will be a break in their operations if they run out of money," he said. "That's why that supplemental legislation was so necessary. Thank you to the House and Senate leadership for bringing everyone back in and assessing that so quickly and responsibly."

Hurricane Irma, a category 4 storm with maximum sustained winds of 155 miles per hour, is expected to hit South Florida by late Saturday and early Sunday.

The storm hit Caribbean islands, including Puerto Rico and the U.S. Virgin Islands, this week as a category 5 storm.

Bossert said the federal government is working to provide aid to the U.S. Virgin Islands and is evacuating U.S. citizens from the affected areas.

As Florida prepares for the storm, mandatory evacuation orders have been in effect for the Florida Keys and parts of the Miami and Fort Lauderdale areas.

Bossert urged those who are under evacuation orders to leave, warning "at some point, people are going to be on their own, so to speak."