(Reuters) - JPMorgan Chase & Co <JPM.N> Chief Executive Jamie Dimon said on Monday that Britain's decision to leave the European Union could lead to duplicate costs to provide banking services to European customers.

Dimon, speaking on CNBC television during a bus tour of bank offices in California, said it is too early to tell how much of the work the bank now does from Britain might have to be done redundantly in Europe.

Dimon also said he thinks the U.S. economy is stronger than it might seem after the government reported last week that gross domestic product increased at a tepid 1.2 percent annual rate in the second quarter.

"I am not even sure that GDP data is actually that accurate any more." Dimon said. "We see more household formation, more people buying homes, more people with jobs."

He said the economy could grow at a 4 percent rate if the next U.S. president makes the right decisions. Reforming immigration laws and improving infrastructure, education and tax credits for people with low income would help the economy, he said.

Dimon did not specifically mention any of the presidential candidates.

(Reporting by Sam Forgione and David Henry in New York; Editing by Phil Berlowitz and Paul Simao)