A “dramatic” drop in opium cultivation in Burma has underscored a regional boom in demand for illegal synthetic drugs such as methamphetamine, which many Asian countries are struggling to combat.

Pope Francis ended a diplomatically tricky trip to Asia on Saturday, seeking the forgiveness of Rohingya Muslim refugees in Bangladesh after his controversial decision to not directly refer to their plight when he visited their homeland, Burma.

Leaders of Asian nations meeting in Manila on Monday skirted around the mass exodus of Rohingya Muslims triggered by Burma’s military crackdown, disappointing human rights groups who were hoping for a tough stand on the humanitarian crisis.

Japan’s ANA Holdings Inc has dropped a plan to form a joint venture in Burma, the airline said on Monday, after its application for an air operator’s certificate (AOC) was rejected by Burmese authorities.

US Secretary of State Rex Tillerson said on Wednesday the United States held Burma’s military leadership responsible for its harsh crackdown on the Rohingya Muslim minority.

With Pope Francis due to visit Burma and Bangladesh next month, a Christian leader from the latter has said he is expecting the Catholic pontiff to urge leaders of the two countries, and the world, to view both Buddhists and Muslims simply as human beings.