US Secretary of State Antony Blinken will return to Brussels this week for discussions on Iran, Afghanistan and Ukraine, a US official said.
Mr Blinken will join US Defence Secretary Lloyd Austin in Brussels, Reuters reported.
Mr Austin was scheduled to visit Nato headquarters in Belgium on a trip that started on Saturday and also includes Israel, Germany and Britain, the Pentagon said last week.
The coincides with increasing tension over Russian activity near Ukraine's eastern border, where Washington says Moscow has amassed more troops than at any time since 2014.
Russian President Vladimir Putin accused Ukraine on Friday of "dangerous, provocative actions" in Ukraine's eastern Donbass region.
Turkey, a Nato ally, said on Friday that the US would send two warships to the Black Sea from April 14 to 15.
Mr Blinken first visited Brussels in March for talks with EU and Nato allies, and pledged to rebuild and revitalise transatlantic alliances.