JPMorgan Chase & Co. Chief Executive Officer Jamie Dimon said the U.S. has legitimate grievances with China on trade, but that “anything that starts to resemble a trade war” will pour risk and uncertainty into the global economic system.

As tensions escalate between the nations, set off by U.S. President Donald Trump’s move to levy tariffs on Chinese goods, Dimon laid out his prescription for solving the debacle in a letter to shareholders Thursday.

The U.S. should set a specific timeline for talks, explain what it hopes to achieve, and stay engaged with both China and allies to avoid the worst outcomes, he said. Resolution of “serious trade issues” would be good for the U.S. and the rest of the world, Dimon wrote.

“We should acknowledge many of the legitimate complaints around trade,” Dimon said. “Tariffs and non-tariff barriers to trade are often not fair; intellectual property is frequently stolen; and the rights to invest in and own companies in some countries, in many cases, are not equal.”

The dispute with China has roiled markets. Dimon, chair of the Business Roundtable, said last month that while there are serious issues with China trade, he opposes the tariffs because “it opens a whole Pandora’s box of additional problems” including the possibility of damage to U.S. growth and investment.

While Dimon has clashed with Trump on issues including trade and immigration, he has supported some of Trump’s other initiatives, including the corporate tax cut that passed in December and his stance on regulations. In his letter, the CEO said that it may be a natural reaction in a time of upheaval “to build walls,” but the U.S. needs to stay engaged with the international community more than ever.

Dimon also addressed risks in financial markets, such as the possibility that the Federal Reserve might have to raise interest rates faster than expected. As long as increases are tied to a strengthening economy and inflation is contained, the central bank’s moves may not be painful, he said.

Yet “many people underestimate the possibility of higher inflation and wages, which means they might be underestimating the chance that the Federal Reserve may have to raise rates faster than we all think,” Dimon said. “While in the past, interest rates have been lower and for longer than people expected, they may go higher and faster than people expect.”

Dimon said that the massive growth in passive investments also makes him worry about the impact of widespread liquidations. Still, the financial system is less leveraged than in the 2008 crisis and consumers have more disposable income, he said.

To support workers, Dimon said the U.S. should expand the earned-income tax credit, get a handle on surging health-care costs and help people learn new skills. If technology, long a benefit to humanity, begins to affect jobs faster than the economy can adjust, “the best protection is continual workforce training, education and re-education, supplemented by income assistance and relocation,” he said.