Panama’s president is warning France that his country will retaliate diplomatically if it is not removed from a list of tax haven countries.

President Juan Carlos Varela said Friday that France has until the end of the year to make the change.

Panama’s financial system was shaken in April by the leak of a huge trove of documents detailing offshore financial dealings. Many of the documents detailed how world leaders, celebrities and businesses used tax shelters to hide money.

Varela says an independent report with recommendations on how to reform Panama’s financial sector will be released Monday.

The two best-known members of the independent study panel, economist Joseph Stiglitz and Swiss anticorruption expert Mark Pieth, left the effort in August over internal differences.