Speaking at a press conference, US State Department spokeswoman Jen Psaki said China has not offered any explanation or background as required by international law for these extended maritime claims. The US lodged its protest after the legislature of China's Hainan province approved rules in November that took effect on January 1 requiring foreign fishing vessels to obtain approval to enter waters under its jurisdiction. China claimed the waters as part of Hainan's new administrative zone in the sea.