A senior EU official said the election of Joe Biden to the White House offers a unique chance to renew the US-Europe relationship, as leaders from the bloc held defence talks.
Some member states are reportedly fearful that a more independent EU could upset President Biden’s push to rebuild relations with the bloc.
"I'm totally convinced that this new Biden administration offers a unique opportunity to renew the strong alliance between Europe and the United States," European Council President Charles Michel said at the start of the video summit between EU leaders and Nato Secretary General Jens Stoltenberg.
"A strong partnership requires strong partners – that's why I'm convinced that a stronger European Union is a stronger Nato,” Mr Michel said.
Mr Biden’s predecessor Donald Trump accused Nato members – many of whom are also in the EU – of underspending on defence. French President Emmanuel Macron, a key proponent of a more autonomous EU, said at the time that Nato was experiencing a “brain death”.
"We share very much the same population, the same members and the same neighbourhood and the same challenges," Mr Stoltenberg said. "It makes it absolutely obvious that we need to work together."
EU foreign policy chief Josep Borrell said the attendance of Mr Stoltenberg was "a clear sign of the close partnership" between the bloc and Nato.
“Our co-operation has been advancing in the past and will continue doing so. There is a strong demand in the current difficult and challenging environment for the EU and Nato to work more closely together,” he said.