Japan’s latest hostage crisis has exposed shortcomings in Japan’s public diplomacy and raises questions about the advice Prime Minister Shinzo Abe received in publicly announcing $200 million in humanitarian aid to help those displaced by conflict with the Islamic State group.

Qatar is working to help free four Americans held hostage in Syria by various armed groups, a Gulf source familiar with the matter said on Monday, a day after the Gulf Arab state's diplomacy helped free a journalist held since 2012.