EU leaders voice concern over Trump

EU leaders will speak up to the US when they think their "principles are trampled on" but say they won't change how they engage with the new Trump government.

Communist-backed Jean-Luc Melenchon has compared German Chancellor Angela Merkel to war-mongering Prussian statesman Otto von Bismarck. Source: AAP

European Union leaders have expressed concern about some decisions and attitudes of the new US administration of President Donald Trump but decided to engage with Washington just the same, Malta's Prime Minister Joseph Muscat says.

Leaders of the 28 countries making up the European Union met on the Mediterranean island of Malta on Friday to discuss migration and the way forward for the EU in the context of Britain's decision to exit the bloc.

"There was concern among the EU 28 on some decisions taken by the new US administration and some attitudes that are being adopted by the said administration," Muscat told a news conference after the first part of the summit.

"There was no sense of anti-Americanism. There was a sense that we need to engage with the US just the same, but we need to show that we cannot stay silent where there are principles involved," he said.

"We have to, and we will speak up when we think these principles are trampled on," he said.