Naypyitaw: Myanmar’s leader Aung San Suu Kyi and the country’s military commander on Wednesday opened a major conference with representatives of ethnic minority groups to try to reach a lasting peace after seven decades of strained relations and armed conflict.

The third session of the 21st Century Panglong Conference is scheduled to last five days and follows meetings held in August 2016 and May 2017. Those sessions failed to make much headway in resolving differences between the government, the military and ethnic rebel groups seeking greater autonomy.

Since 2015, the government has promoted a cease-fire agreement that several ethnic minority groups have signed. However, some other major rebel groups, especially in the country’s north, are wary of committing to the deal until political terms are made clearer.

The event is named after the original 1947 conference convened by Suu Kyi’s father, Gen. Aung San, who was head of an interim government while his country — then called Burma — prepared for independence from Britain. An agreement brokered by Aung San and signed by several major ethnic minority groups granted minorities significant autonomy and the right to secede if they joined a post-independence federal union. But Aung San was assassinated shortly after and the deal fell apart.

Since then, ethnic groups have accused successive, mostly military governments of failing to honor the 1947 pact.

Despite the framework of the conference allowing only the cease-fire signatories to attend, the Myanmar government invited a political alliance of non-signatory armed ethnic groups from the north of the country, often referred to as the Northern Alliance, to attend the conference.

The non-signatories will be allowed to attend the group discussions, but will not be permitted to speak, said government spokesman Zaw Htay.

Suu Kyi has previously called on all armed ethnic groups to sign the cease-fire. Her National League for Democracy-led government promised that peace would be the top priority when it came to power in 2016, but has since come under fire the brutal military crackdown on Rohingya Muslims, as well as for failing to stop atrocities against other ethnic minorities.