Japan today pledged to provide up to $500 million in grant aid to countries affected by the tsunami, which has killed more than 127,000 people.
The Japanese aid, the biggest by a single country so far, would raise the total promised to about $1.86 billion.
"This is the upper limit of what we are willing to provide," Foreign Ministry assistant press secretary Mr Akira Chiba told Reuters.
The actual amount to be disbursed would depend on projects and programmes to be agreed among donors, he said.
Prime Minister Mr Junichiro Koizumi is to attend a meeting of world leaders in Jakarta on Thursday to discuss aid plans, the ministry said in a statement.
Japan had initially pledged $30 million in aid to countries affected by the earthquake-generated tsunami that hit countries around the Indian Ocean on December 26th.
The US raised its aid tenfold yesterday to $350 million.