Japan's House of Councilors has unanimously passed a resolution, condemning the coup d'état in Myanmar and calling for early recovery of the democratic political system.

At the main meeting on Friday, bipartisan lawmakers of Japan's upper house of the parliament, such as the Liberal Democratic Party and the Constitutional Democratic Party have submitted resolutions to the House of Councilors over the situation in Myanmar, according to Japan Broadcasting Corporation, NHK.

It pointed out that the coup d'état that occurred in February was "a trampling of efforts and expectations for democratisation, and the legitimacy of the current system by the military is not recognised at all" to civilians by the military and police.

"We strongly condemn the situation where the violence continues and many people are killed or injured. On top of that, we urge military leadership to immediately stop atrocities against civilians and immediately release detained Aung San Suu Kyi and others," the resolution said.

In addition, the House of Councilors said they will make full use of all diplomatic resources for the government of Japan, make every effort to realise an early recovery of the democratic political system, provide emergency assistance to displaced people, and work toward a ban on arms exports to the military.

A similar resolution has been passed by the House of Representatives regarding the situation in Myanmar last Tuesday.

The move reflects Japan's intention to show its opposition to the Myanmar junta as Group of Seven summit happens in UK.

It said the military junta "cannot be justified at all" and expressed "solidarity with the people of Myanmar", in reference to peaceful protesters.

The resolution said Tokyo would have no choice but to review its existing development aid toward Myanmar and that investment by Japanese firms could suffer if the situation does not improve.

"We will decide our economic cooperation going forward based on how Myanmar addresses these issues," Japan's Chief Cabinet Secretary Katsunobu Kato said at a press conference, reports Kyodo News.

Japan has put on hold new official development assistance for the Southeastern Asian country in response to the coup.

More than four months after the military takeover, the junta's violence against civilians continues with the number of people killed surpassing 850, according to a human rights group monitoring the situation in Myanmar.

Myanmar military took over power on February 1, ousting the elected leaders of the National League of Democracy (NLD), alleging elections fraudulence in November last year.

Following the coup, NLD leaders and some other independent and ethnic leaders formed the National Unity Government in exile and last month formed Peoples' Democratic Forces, an armed wing of the shadow government.

UN Human Rights Commissioner Michelle Bachelet on Friday said the violence was escalating across Myanmar, warning that the country had plunged into a "human rights catastrophe" since the February 1 coup.