Tonga's government says it needs at least 50 million US dollars worth of climate funding to deal with issues like coastal erosion.
The Environment and Climate Change Minister Siaosi Sovaleni said the country would apply to the UN's Green Climate Fund in April for most of that amount.
Mr Sovaleni said communities needed help with coastal protection measures, sedimentation management and capacity building.
He said the Eastern and Western coasts of Tongatapu and the islands of Ha'apai were particularly vulnerable.
"Most of our roads tend to be on the coastline and if we don't do something about it, it will also affect those key infrastructure and that will affect people down the road who actually need those roads for transportation," said Siaosi Sovaleni.
Mr Sovaleni said work also needed to be done around marine life and coral protection in Vava'u.
Tonga should find out by August whether their application is successful.