The European Union's economic and financial committee has criticized U.S. President Donald Trump's economic policy and is worried that his efforts to boost protectionism pose a threat to the global economy, a German magazine reported.

"The effects of that could be much more damaging than had been thought until now," Der Spiegel said, citing an internal paper from a committee of top officials from the finance ministries of EU member states.

It also said the Europeans were concerned by the Trump administration's spending plans, saying that because "public debt is already on a path that is not sustainable" this policy contained "short-term risks for the global economy."

It said lenders had recently avoided the United States.

"The decline in international investments is a possible vulnerability," Der Spiegel cited the paper as saying of the United States.

It also said plans to reform taxes in a way that would especially reduce the burden on top earners would "exacerbate the challenges the U.S. economy faces rather than alleviate them".

Trump has listed his broad principles for tax reform as simplifying the U.S. tax code and providing tax relief to middle-class Americans, ideas he has been talking about since his 2016 presidential campaign.

The European Commission declined to comment when contacted by Reuters. A spokesman for the Estonian Presidency said he was unaware of any paper singling out Trump.