Suu Kyi was scheduled to give a speech at Sydney's Lowy Institute on Tuesday but the think-tank announced she had been forced to cancel as she was "not feeling well," in a statement Monday afternoon.
"Following the speech, the State Counselor was to take questions from the audience," the statement said.
Hours after the speech was canceled, Myanmar government spokesman Zaw Htay told CNN Suu Kyi had felt "jet lagged and a bit weak" but was now fine and spending the afternoon with the Australian Myanmar community.
When pressed as to whether the event would be rescheduled, Zaw Htay said in a text: "Schedule is very tight, it's not suitable for her. We're very sorry to cancel it."
Suu Kyi was in Sydney on Saturday for the first ASEAN (Association of Southeast Asian Nations) meeting to be held in Australia. On Monday morning she met with Australian Prime Minister Malcolm Turnbull in Canberra.
Bangladesh and Myanmar have agreed to send some of the refugees back across the border, but so far only around 8,000 Rohingya have applied to be sent home.
During her visit she has been met with criticism and protests by local Rohingya groups, who issued a statement calling for Turnbull to raise the ongoing human rights crisis with the Myanmar leader.
"We want Australia as a member of the UN Security Council to take action to end the ongoing ethnic cleansing in Myanmar and we want Australia to stop military aid or any business with the government," Australian Burmese Rohingya Organization spokesman Habiburahman told CNN.
Turnbull told reporters Sunday that Suu Kyi made a lengthy speech calling for humanitarian assistance and capacity building to help deal with the Rohingya crisis during the ASEAN meeting.
Suu Kyi broke her silence about the unfolding Rohingya crisis in televised address in September, saying her country wasn't "afraid of international scrutiny." She has not spoken publicly on the subject since.
Alistair Cook, research fellow at the S. Rajaratnam School of International Studies, told CNN Suu Kyi's statement to ASEAN was an unremarkable move to tackle an issue the Myanmar leader knew would be raised at the summit.
"The region is well aware of (the crisis) and they're trying to get some indication of what's being done there and how cooperation can be furthered," he said.
It is understood Suu Kyi's requests for aid were discussed during Turnbull's meeting with the Myanmar leader, but a spokesman for the Prime Minister wouldn't confirm whether any deals had been reached.
"The solutions to this crisis lie inside Myanmar, and conditions must be established that will allow refugees to return home," UN High Commissioner for Refugees Filippo Grandi said in a statement.
"But today we are appealing for help with the immediate needs, and these needs are vast."