The United Nations children's agency, Unicef, has urged the international community to prioritise youngsters made orphans by the tsunami disaster.
Thousands of children have lost families and homes
Unicef head Carol Bellamy made the plea ahead of a donors' meeting on Thursday.
As many as 50,000 children were killed, and more than a million have been hurt or lost families in the disaster.
Ms Bellamy was speaking as US Secretary of State Colin Powell arrived in Aceh province in Indonesia, the worst-hit area, to see the damage for himself.
Mr Powell - who is to attend Thursday's conference on the relief effort in the capital, Jakarta - said humanitarian relief was part of "American values".
Indonesia is his last stop in his tour of countries hit by the sea surges.
In other developments:
- Tsunami survivors in India's Andaman and Nicobar islands say crocodiles searching for food have become a menace
- Shops re-open in villages in eastern Sri Lanka for the first time since the waves hit on 26 December
- The first six bodies of 52 Swedish tourists killed in the tsunami arrive in Stockholm from Thailand. A further 827 Swedes are still missing
- The European Union is to observe a three-minute silence at midday on Wednesday to honour the victims
- The US military says it may well double the number of helicopters it has deployed to Asia to help with the relief efforts.
Unicef said it had identified four priorities the Jakarta meeting must take on board to help what it calls the "tsunami generation" of children.
They include ensuring children get clean sanitation, water and nutrition; caring for, identifying and trying to reunite those separated from families; protecting them from exploitation; and ensuring they get back to school as quickly as possible.
"I'm not satisfied that the global relief effort is focused enough on the more than 1.5 million children made vulnerable by this calamity," said Ms Bellamy.
TSUNAMI'S CHILD VICTIMS
Children account for 40% of Sri Lanka's known death toll
Thai officials say more than 300 children have lost one or both parents
Criminal gangs are said to be befriending children to sell them on to sex traffickers
Earlier, the Indonesian government banned children from leaving the devastated province of Aceh after Unicef warned that child traffickers could be trying to exploit the situation.
The ban was set to stay in place until a clearer picture emerged of the status of the tens of thousands of children separated from their families, the UN agency said.
And in the southern Indian state of Andhra Pradesh, a Save the Children Fund worker told the BBC of concerns that children were being taken away from relief centres by strangers.
Swedish police are already in Thailand investigating reports that a 12-year-old Swedish survivor of the tsunami was kidnapped from a hospital in the chaotic aftermath.
"It's been over a week and every passing day is now critical," said Ms Bellamy. "All of us have to focus on these priorities for saving children, and we have to do it now."
UN Secretary General Kofi Annan and senior politicians from around the world are making their way to the Jakarta conference.
Donors will focus on coordinating the massive aid and recovery efforts, and are also likely to consider establishing a tsunami alert system for the Indian Ocean region.