Donald Trump has frequently spoken about the need for NATO allies to increase the amount they spend on defense.

NATO Secretary General Mark Rutte told members of the security alliance to boost defense spending or prepare to learn Russian. Speaking at the European Parliament in Strasbourg, France, Monday Rutte told European lawmakers that they have to urgently rethink spending priorities to ensure their security.

NATO secretary-general rained fire on EU members of the U.S.-led bloc over defence spending on Monday. Mark Rutte told an European committee that members need to increase their defence spending or learn Russian as they could face an attack anytime after 4-5 years.