St Lucia will soon become the latest Caribbean country to allow far-flung investors to buy local citizenship.

Prime Minister Kenny Anthony told a "global citizens forum" in the wealthy principality of Monaco that St Lucia will start accepting applications for a citizenship-by-investment programme in January.

A Friday government statement said Anthony made the announcement at a gathering of investors, wealth managers and citizenship lawyers.

It's part of a trend in the Caribbean to boost revenue on islands struggling with oversized debt. The nearby islands of Dominica, St Kitts & Nevis, Antigua & Barbuda and Grenada allow global investors to secure local citizenship in return for a donation or investment.

The islands offer a much faster, easier and cheaper path to citizenship than countries with "investor visas" like the United States.