The foreign ministers of Germany, France and Britain plan to hold nuclear talks with their Iranian counterpart on Friday in Geneva, a German diplomatic source told Reuters.

The ministers will first meet with the European Union's top diplomat, Kaja Kallas, at Germany's permanent mission in Geneva before holding a joint meeting with the Iranian foreign minister, the source said.

The European initiative comes amid fears of a spiralling conflict in the Middle East after Israel launched wide-ranging military strikes on its arch-enemy Iran last week and Iran sent waves of missiles at Israeli targets in response, according to Reuters.

President Donald Trump has declined to say whether the United States will join its ally Israel's military campaign, fuelling concerns that the crisis could intensify.