NATO chief Mark Rutte and the new U.S. ambassador sought to reassure European allies on Thursday that Washington will remain committed to the Western military alliance despite harsh words from President Donald Trump.

Rubio is at a meeting of NATO foreign ministers at which many are hoping he will shed light on U.S. security plans in Europe.

BRUSSELS—US Secretary of State Marco Rubio and the Trump administration’s new envoy to NATO are seeking to reassure wary NATO allies of the US commitment to the alliance. Rubio on Thursday decried “hysteria and hyperbole” in the media about President Donald Trump’s intentions despite persistent signals from Washington that