A book of condolence has been opened for Nóra Quoirin at Belfast City Hall.
The Mayor of Belfast, John Finucane, was the first person to sign it on Wednesday afternoon.
He said: "My deepest sympathies are with Nóra Quoirin's family."
My deepest sympathies are with Nóra Quoirin's family.
As a mark of respect, I will open a book of condolence on behalf of Council, & the people of Belfast, in City Hall at 3.30pm today.
— John Finucane (@johnfinucane) August 14, 2019
Meanwhile, police in Malaysia have said they still cannot reveal a cause of death for the 15-year-old teenager.
At a briefing just after 1.00pm, police said they could confirm the cause of death until a post mortem examination was complete.
A further update is expected on Thursday morning.
Earlier, the family said the "cruelty of her being taken away is unbearable".
They released a statement following the discovery of her body in Malaysia on Tuesday.
Her body was found following a 10-day search involving hundreds of police and volunteers.
Nóra's family has thanked everyone involved in the search for their efforts to find her.
They said: "We thank the local people here and those far and wide for their prayers and support at this time.
"Nóra has brought people together, especially from France, Ireland, Britain and Malaysia, united in their love and support for her and her family. She has truly touched the whole world.
"To all our friends and family at home, we can’t thank you enough for all your love."
Their statement added: "Nóra is at the heart of our family. She is the truest, most precious girl and we love her infinitely.
"The cruelty of her being taken away is unbearable. Our hearts are broken. We will always love our Nóra."
Nóra's body was found shortly before 2.00pm local time on Tuesday in a hilly area around 2km away from the resort she disappeared from.
Her remains were then airlifted to a local hospital, where the Quoirin family identified them as that of the missing 15-year-old.
Nóra was reported missing from the Dusun Holiday Resort near Kuala Lumpur, where she was staying with her parents, on Sunday August 4th.
The family had arrived at the resort the night before and woke to find her gone the following morning.
Political leaders here, including the Taoiseach and President, have offered their condolences to the family.
President Higgins also expressed his gratitude on behalf of the Irish people to everyone who assisted and supported the search.
Additional reporting: Jack Quann