The Obama administration is sending hundreds of federal agents to Louisiana to respond to last weekend's disaster, but don't expect the president to show up, Homeland Security Secretary Jeh Johnson said Thursday.

"The president can't be everywhere," said Johnson, after repeatedly being prodded by reporters at a press conference about a presidential visit. He said the "president is closely monitoring" the situation "and is very much on top of it."

Johnson said President Obama "has a very busy schedule in the fall" and in the coming days and likely won't make the trip.

"I will be briefing the president on the situation that I see here at some point very soon," he said.

Democratic Louisiana Gov. John Bel Edwards, who joined Johnson, backed him up by saying the president would be welcomed to visit, but it wouldn't be the best time.

He said the police and security coordination required for a presidential visit would be difficult for the state to pull off right now.

"The president is welcome to visit whenever he wants to visit, and when he wants to visit we are going to receive him," Edwards said.

"However, if you would remember a few weeks ago when the vice president came for the memorial of the police officers that were shot and killed, if you will recall the impact that had on the community with respect to closing down interstates, the security that was required and all of the police officers locally that had to be taken from other duties," he said. "Quite frankly that is not something I want to go through right now."

Johnson tried to demonstrate that the government is committed to seeing the relief effort through to completion after more than 40,000 homes were destroyed by extreme flooding.

"The federal government is here, we have been here, we will be here as long as it takes to help this community recover," he said. "The president has declared a major disaster declaration affecting 20 parishes. That means fundamentally two things: individual assistance to those that have been personally affected … and public assistance."

Some 86,000 people have applied for federal assistance, which includes assistance in home repairs, he said. Once eligible for Federal Emergency Management Administration assistance, "money can be transferred to you in a matter of just a few days," Johnson said.

"We are here to provide public assistance as well in terms of the repair of infrastructure roads and schools," he said. "At present there are some 950 FEMA personnel on the ground. We expect another 750, possibly more, in the coming days."

The Red Cross is contributing cots, meals, blankets, water and other necessities.

The Coast Guard is also in the state "on the job," Johnson said. The Coast Guard was the first Homeland Security branch to respond to the flooding with search and rescue operations. "The Coast Guard continues to monitor the situation of the rivers, monitor the water levels," Johnson said.

The Small Business Administration is also there to help small businesses.

"This has been a reaffirmation in terms of our ability to pull together at the state, local and federal level" when disaster strikes "to help the people we are sworn to serve," Johnson said.