US President Donald Trump on Thursday met leaders of the main European Union institutions here as part of his first international tour after taking office in January.
After Tusk, Trump met European Commission President Jean-Claude Juncker and they were later joined by European Parliament President Antonio Tajani and the EU's top diplomat Federica Mogherini, Efe news reported.
"EU and the US must remain close allies to protect citizens against terrorism, boost growth and jobs for future generations," Taajni posted on Twitter alongside images of the talks.
US Defense Secretary James Mattis, Chief Economic Advisor Gary Cohn, National Security Advisor H.R. McMaster and Secretary of State Rex Tillerson accompanied Trump.
"Transatlantic relations key to world safety, prosperity," posted EU Commission spokesman Margaritis Schinas on Twitter.
"Strong EU/US ties at the heart of global agenda," he added.
The US President will have lunch with his French counterpart Emmanuel Macron at the American Embassy before the NATO meeting.
Trump will meet British Prime Minister Theresa May during the summit, where she was expected to confront him about confidential information leak on the Manchester bombing to the US press.