WASHINGTON — The White House is asking Congress for more than $14 billion as a down payment on Hurricane Harvey recovery efforts, sending Republican leaders a request late Friday for $7.8 billion in immediate aid that will be quickly followed by a request for another $6.7 billion, officials said.

The initial funding represents only a fraction of the long-term storm relief for flood-ravaged parts of Texas and Louisiana, which is likely to far exceed the $50 billion in funds allocated to northeastern states in the wake of Hurricane Sandy in 2012.

President Trump is expected to make a pitch for quick passage of storm funding legislation when he travels on Saturday to the Houston area and to Lake Charles, La., his second trip to the region in the week since the hurricane made landfall at Rockport, Texas, inundating the Gulf Coast with record-breaking floods and rainfall.

The first, stand-alone bill would channel the vast majority of the funds to the Federal Emergency Management Agency and the rest to other agencies, including $450 million for the Small Business Administration. Representative Nancy Pelosi of California, the House minority leader, told fellow Democrats that the White House budget director, Mick Mulvaney, would not be seeking offsetting spending cuts, as he insisted on for other emergency spending when he was a conservative member of the House.