Global growth will motor along, but the recovery will be gradual and uneven with heightened uncertainty, even as the United States, the world’s biggest economy, is expected to recover, the ECB said in a regular economic bulletin.

“A key downside risk is a stronger slowdown in emerging markets, including China,” it said.

A tightening of financing conditions and an increase in political uncertainty could exacerbate existing macroeconomic imbalances, denting confidence and resulting in an unexpectedly strong slowdown.

The bulletin was largely consistent with the outlook presented at the ECB’s September rate meeting.

“Policy uncertainty surrounding the economic transition in China could lead to an increase in global financial volatility,” the ECB said.

“Continued emphasis on rebalancing the economy—including reductions in overcapacity in some heavy industries and action to address non-performing loans—is expected to result in a decline in the pace of economic growth,” it added.

Although Brexit has so far had limited impact and some analysts have lifted their gloomy forecasts, the ECB warned that the worst may not be over.

“The economic implications of the United Kingdom leaving the European Union could be worse than expected, increasing uncertainty and negatively affecting trade, business confidence and investment,” it said.

Although monetary and fiscal accommodation should support the British economy, the institutional and political uncertainty surrounding the negotiations are expected to dampen domestic demand, particularly investment, even if the short-term impact has been modest, the bank said.