The United States and Britain on Friday urged China to reflect on "serious concerns" about Hong Kong's autonomy at a UN Security Council meeting swiftly denounced by Beijing. "We hope the Chinese government will pause and reflect on the serious and legitimate concerns this proposal has raised both within Hong Kong and around the world," said Jonathan Allen, Britain's deputy permanent representative. China enjoys veto power at the Security Council and blocked a formal meeting on Hong Kong. But the United States and Britain insisted on raising their alarm at a more informal, closed-door Security Council session where Beijing cannot block the agenda. China's ambassador to the United Nations, Zhang Jun, urged the United States and Britain "to immediately stop interfering in Hong Kong affairs." "Any attempt to use Hong Kong to interfere in China's internal matters is doomed to fail," warned a statement from China's UN mission. China moved ahead this week with a controversial security law that bans subversion and other perceived offenses in the financial hub. Many Hong Kongers say the law will effectively end the freedoms that were promised by Beijing before regaining control of the territory from Britain in 1997. prh-sct/sst