Myanmar's government alleged the reporters were arrested because they "illegally acquired information with the intention to share it with foreign media", according to CNN.
Ko Wa Lone and his colleague Ko Kyaw Soe Oo have been detained by police since December 12 and are charged under Section 3 of the colonial-era Official Secrets Act for allegedly acquiring information from police officers about the violence in northern Rakhine State illegally.
They had worked on coverage of a crisis in the western state of Rakhine, where a military crackdown that followed militant attacks on security forces in August led to an exodus of more than 650,000 Rohingya Muslims to refugee camps in Bangladesh.
Myanmar journalist Thet Oo Maung, known as Wa Lone, right, stands in 2014 with other journalists with their mouths taped, symbolising the government's crackdown on the media.
The two journalists arrived and left court in handcuffs.
Reuters correspondent Andrew Marshall said his colleagues "are innocent men who were arrested for doing their jobs" and also called for their release. "We believe time is of the essence and we continue to call for Wa Lone and Kyaw Soe Oo's prompt release", he said. The journalists are being held in the notoriously harsh Insein✓ prison in Yangon.
Surakiart Sathirathai, a former Thai foreign minister and the head of a new worldwide advisory panel on the Rohingya crisis, also expressed concern at the arrest of the reporters and said he hoped the case did not lead to broader restrictions on the global media.
Wa Lone and Kyaw Soe Oo were allegedly working on a story related to the recent eruption of violence in the northern Rakhine State where hundreds of people were killed in clashes with government forces and the Arakan Rohingya Salvation Army (ARSA).
"The United States is deeply disappointed by today's court decision", the State Department said Wednesday as it reiterated that call.
Kristian Schmidt, the European Union's representative to Myanmar, raised concerns about the arrest of the two journalists and uged their release in a letter to Myanmar's de facto leader Aung San Suu Kyi on Monday.
Pressure from prominent individuals in the worldwide community and rights groups is mounting on the Myanmar government to release two Reuters journalists detained in December on charges of violating the country's colonial-era Official Secrets Act, with former U.S. President Bill Clinton now calling for their immediate release.
Government officials from some of the world's major nations, including the United States, Britain and Canada, as well as top U.N. officials, have called for the release of the journalists.
"The charges against us are wrong and unfair".
Also on Tuesday, London-based Amnesty International urged Myanmar authorities to immediately release the pair.
Japan wants to raise the matter of the two reporters with the Myanmar government at appropriate opportunities, including a visit by Japanese Foreign Minister Taro Kono this week, Japan's Chief Cabinet Secretary Yoshihide Suga said in Tokyo.
Human rights and media groups have criticised the government for threatening journalists. She has made no public comment on the case of the two Reuters reporters.