12:49 pm ET: Dimon called the US-China relationship the most important in the world for the next 100 years.
He said that after some initial reluctance, Corporate America supports efforts to reform China's trade practices.
"The business community can get very selfish when it comes to trade," DImon said.
He sounded cautiously optimistic about progress on trade talks.
"This has to be fixed. I think China knows and is serious. You now have serious people on both sides that are actually talking," Dimon said.
12:41 pm ET: JPMorgan is prepared in case the United Kingdom to crash out of the European Union.
"A hard Brexit will be a disaster for Great Britain. We don't think it will happen because it's bad for Europe," Dimon said.
Instead, Dimon suggested negotiations would be extended if needed.
Still, JPMorgan has spent hundreds of millions of dollars to prepare in case he's wrong.
"The Brits were dealt a bad hand — and they played it badly," he said.
12:35 pm ET: Dimon warned that another government debt ceiling scare would be an "unmitigated disaster."
He said that JPMorgan spent $50 million to $75 million preparing for the 2011 debt ceiling impasse.
12:25 pm ET: Jamie Dimon is frustrated with Washington.
The JPMorgan Chase (JPM) boss called the government shutdown a "self-inflicted wound" that is a "negative" for the economy.
"You can't have a democracy where you refuse to compromise," Dimon said while speaking at a Manhattan luncheon hosted by the Economic Club of New York.
Dimon urged Washington to focus on reforming America's education, infrastructure, immigration and trade policies.