The Solomon Islands opposition foreign affairs spokesman, Alfred Sasako, says aid donors must provide more help or risk that Solomon Islands becomes a terrorist haven.
Mr Sasako says the deal the government has signed with the group, the Royal Assembly of Nations and Kingdoms, has damaged the country's reputation and integrity beyond repair.
The group says a 350 million US dollar grant will be given this week.
He says with aid donors yet to fully re-engage in the country, the government has been driven to an act of desperation which sends a signal that it is prepared to deal with terrorists and international gangsters.
"There is a lot of money in those kind of activities and if they know that here is a legitimate government that is willing to take money for anything I believe that Solomon Islands has become the first country in the region to open its doors for these sort of people to come in."
He says what the international community does now will determine the future of Solomon Isalnds.