The lawsuit stems from an account set up with a $2 million deposit by Marcos in 1972 at Merrill, Lynch, Pierce, Fenner & Smith Inc. in New York. Merrill Lynch went to court in 2000 to determine who the money belonged to.
The Philippines government asserted sovereign immunity and said the case could not proceed in U.S. courts.
The willingness of lower U.S. courts to nonetheless get involved "raises significant concerns," the U.S. solicitor general said in a filing with the Supreme Court.
The ruling by the 9th U.S. Circuit Court of Appeals in San Francisco prejudices cases in the Philippines on the same issue, the solicitor general said in court papers.