The toppled leader, who faced criticism from rights groups for her involvement in the alleged Rohingya genocide, is now under trial by the same generals she defended in The Hague.
Myanmar's junta is set to replace Aung San Suu Kyi at the UN's top court as it seeks to dismiss a case over the alleged genocide of Rohingya Muslims.
In its "preliminary objections" on Monday, Myanmar will argue that the court has no jurisdiction over the case, and must throw it out before it moves on to substantive hearings.
Suu Kyi personally presented Myanmar's arguments at the International Court of Justice (ICJ) when the case was first heard in December 2019, but was ousted as civilian leader in a military coup last year.
The Nobel peace laureate, who faced criticism from rights groups for her involvement in the case, is now under house arrest and trial by the same generals she defended in The Hague.
Local Myanmar media said the junta has a new delegation led by Ko Ko Hlaing, international cooperation minister, and Thida Oo, attorney general, who will attend virtually.
Both have been hit with US sanctions over the coup.
The case brought by the mainly Muslim African nation of The Gambia accuses predominantly Buddhist Myanmar of genocide against the Rohingya minority over a bloody 2017 military crackdown.
The ICJ made a provisional order in January 2020 that Myanmar must take "all measures" to prevent the alleged genocide of the Rohingya while the years-long proceedings are underway.
Gambia will make its counter-arguments on Wednesday.
Around 850,000 Rohingya are languishing in camps in neighbouring Bangladesh while another 600,000 Rohingya remain in Myanmar's southwestern Rakhine state.
The ICJ was set up after World War II to rule on disputes between UN member states. Its judgments are binding but it has no real means to enforce them.
The Rohingya case at the ICJ has been complicated by the coup that ousted Suu Kyi and her civilian government, and triggered mass protests and a bloody military crackdown.
More than 1,500 civilians have been killed, according to a local monitoring group.