The leaders of the Quadrilateral Security Dialogue (Quad) have expressed shock at the tragic assassination of former Japanese Prime Minister Shinzo Abe, the White House said on Friday.

"We, the leaders of Australia, India, and the United States, are shocked at the tragic assassination of former Japanese Prime Minister Shinzo Abe. Prime Minister Abe was a transformative leader for Japan and for Japanese relations with each one of our countries," the statement read.