European Central Bank President Mario Draghi warned EU leaders that protectionist trade stances and increasing public spending represent the primary risks to the otherwise positive economic outlook for the region, Reuters and Bloomberg News reported, citing sources familiar with the discussions.

Draghi said trade protectionism was among the biggest risks to economic growth, with tariffs and retaliatory measures potentially undermining confidence.

Draghi also said fiscal policies in the U.S. and EU have become "pro-cyclical" as states are increasing public spending, which could cause overheating of economies.

Two other risks to expansion are financial deregulation and the repricing of assets in the U.S. that could affect the European economy, Draghi added, according to the reports.

Draghi raised these concerns in a presentation to German Chancellor Angela Merkel and other European leaders gathered in Brussels, the reports said.

The ECB chief said the favorable outlook on the European economy was due to rising investment levels not seen in about a decade, falling private sector debt, and banks' improving capital ratios.