TOKYO -- An environmental group says an undercover investigation has found loopholes and weaknesses that make Japan a weak link in efforts to curb a resurgence in the illicit trade in ivory.

The report released Thursday by the Washington, D.C.-based Environmental Investigation Agency, based on surveys during 2015 of ivory traders based in Japan, found that most were open about their ability to evade controls.

It said much of the ivory sold through online retailers based in Japan is going to China.

Ivory is often used for ornate traditional seals and decorative items. Poachers have annually killed tens of thousands of elephants in recent years to meet rising demand for ivory, particularly in China. In September, the United States and China agreed to work toward nearly complete bans on the ivory trade.