Before leaving New Zealand, Ardern told the Herald she was unsure whether Aung San Suu Kyi would be attending the meeting but confirmed she would be raising the Rohingya issue if she got a meeting.
"Certainly if I did, I absolutely would."
The pair met at the Apec summit in Vietnam last year where Suu Kyi was a guest, and at the East Asia Summit in the Philippines where it was discussed.
"There is a huge awareness of the human rights issues, the displaced and I expect it will be raised by a number of members [this year]," Ardern said.
"There's no denying the impact has been incredible on Rohingyas – every account."
It is expected to be on the agenda of the East Asia Summit again on Thursday.
Ardern's meeting with Suu Kyi was confirmed late last night and is due to take place at 3.30 pm today.
Aung San Suu Kyi was held under house arrest for many years as the leader of the democracy movement under a military dictatorship and was awarded the Nobel Peace Prize.
The country opened up from 2010 and held its first democratic elections in 2015.
She is constitutionally barred from standing as president but as State Counsellor is effectively head of the Government.
Former Prime Minister John Key visited Myanmar in 2012.
Ardern is today also meeting the Thai Prime Minister, retired general Prayut Chan-o-cha, Australian Prime Minister Scott Morrison, and China's Premier, Li Keqiang.
She will attend a meeting of countries negotiating the Regional Comprehensive Economic Partnership and go to a gala dinner where she will be sitting with US Vice President Mike Pence.
On Thursday she is due to meet Japanese Prime Minister Shinzo Abe and Malaysian Prime Minister Mahathir Mohamad.