European Commission head Ursula von der Leyen won't be attending Donald Trump's inauguration in Washington on January 20, but hopes to have "early contacts" with the incoming administration, Brussels said Friday.

"There has been no invitation and there are no plans to attend," EU spokeswoman Paula Pinho said. "We will be seeking early contacts with the new administration."

Foreign leaders are by tradition not invited to attend the inauguration of the US president, although Trump reportedly asked Chinese President Xi Jinping to attend this time round.

Von der Leyen, who has been suffering from severe pneumonia in recent weeks, did not attend the inauguration of Joe Biden four years ago. 

The EU is nervously eyeing the return of the volatile former reality TV star to the White House at a perilous moment for Europe. 

The incoming US leader has pledged to end Russia's war in Ukraine and European allies are desperate to convince him not to force a bad deal on the continent. 

They are also scrambling to avoid trade tariffs that Trump has mooted.

Trump on Tuesday already set off a political firestorm by refusing to rule out using military force to seize Denmark's autonomous territory Greenland. 

Von der Leyen insisted on Thursday that the EU "will always protect our citizens and the integrity of our democracies and freedoms."

But she insisted the "US is one of our closest partners and we are committed to strengthening the Transatlantic bond."