NUKU'ALOFA (Tonga), April 5 -- More than four years on from one of the most powerful volcanic eruptions in history, Tonga is struggling to improve its infrastructure as it pays off a massive Chinese loan.

When Hunga Tonga-Hunga Ha'apai erupted on January 15, 2022, the blast could be heard as far away as Alaska and sent a powerful tsunami crashing into Tonga's main island some 65 kilometres away, killing three people.

Hundreds of homes were destroyed, businesses flattened and roads washed out, while most water supplies were left undrinkable as six inches of ash fell on the Tongan islands.

Tongan Prime Minister Lord Fakafanua said last month that most government programmes to rebuild were complete, but conceded there were "some leftovers...