The US accounted for the majority of arms imports by European NATO states in the last four years, a Swedish research group found, highlighting their dependence at a time when transatlantic relations are fraying.

European arms imports rose 155% in 2020-24 and Ukraine has become the world's biggest arms importer following Russia's 2022 invasion, according to a report released by a leading conflict think tank on Monday.

Ukraine and European NATO countries are dependent on arms supplies from the USA. American imports constitute 45 percent and 64 percent of their supplies, respectively, according to a report by the Stockholm International Peace Research Institute (SIPRI).