A United Nations human-rights expert is calling for more sanctions on Myanmar's ruling junta to choke off its sources of money.
UN Special Rapporteur Thomas Andrews warned that the humanitarian situation is deteriorating as the military steps up its attacks on civilians.
Andrews was speaking in a news conference in Tokyo on Friday.
He said more than 3,400 civilians have been killed, and some 17,000 political prisoners detained since the military took power in a coup two years ago.
He cited airstrikes in the northwestern region of Sagaing earlier this month that killed about 170 people.
He said economic sanctions aimed at depriving the junta of the resources to operate its war-making machinery would weaken its capacity to attack the people of Myanmar.
He urged Japan, as chair of this year's Group of Seven meetings, to join Western countries in imposing sanctions on the military. He called for a strong message at next month's G7 summit in Hiroshima.
Andrews also urged the international community to expand humanitarian aid for Rohingya Muslim refugees who fled Myanmar to escape deadly attacks by the military. Around a million are still living in camps in neighboring Bangladesh.
He said UN food distribution has been significantly reduced because of a lack of funding, and over 40 percent of the children suffer from malnutrition.