"Too many totalitarian states hide the reality of victims of terrorism in their country in order not to be accountable for them to the world," she said at Tuesday's conference.
The one-day conference was addressed by survivors and relatives of those affected by attacks in countries including Russia, Kenya, Jordan, Indonesia, Tanzania, India and Britain.
"It is indispensable to provide an international status to the victims of terrorism," said Betancourt, focusing mainly on those held hostage.
Betancourt also called for the UN to set up a website that contained information about those held by armed groups.
Being officially recognised by the United Nations would mean someone could be sponsored by a state, a town or an organisation to follow their case and support their family's campaign, she said.
'State-sponsored' attacks
Some critics, however, condemned the meeting for not also inviting those affected by state or state-sponsored attacks.
Riyad Mansour, the Palestinian representative to UN, told Al Jazeera: "We identify fully because we live these feelings and we are the biggest victims of terrorism in the Middle East."
Ban Ki-moon, the UN secretary-general, also addressed the gathering, paying tribute to those present as well as "to all those who have been victims of terrorism in far too many places".
"Your stories of how terrorism has affected your lives are our strongest argument why it can never be justified," he said.
"By giving a human face to the painful consequences of terrorism, you help build a global culture again."