MOSCOW (Reuters) - Russia has revoked the residence permit of a U.S. human rights worker on national security grounds and ordered her to leave within two weeks, a spokeswoman for the organisation she heads said on Thursday. Vanessa Kogan, director of the Justice Initiative rights group, an organisation that provides legal assistance to rights victims, particularly from the turbulent North Caucasus region, has lived in Russia for 11 years, Ksenia Babich, the spokeswoman, told Reuters. Kogan is married to a Russian citizen, has two children and applied for Russian citizenship several months ago, but was told on Wednesday that the Federal Security Service (FSB) had not approved her application and had also told her to leave. Officials cited legislation allowing them to revoke her residency rights if she had made calls for a “violent change of the constitutional regime” or posed “a danger to Russian national security or its nationals,” Babich said. Kogan, who denies making any such calls, has three days to appeal the order and plans to do so, she added. The FSB did not immediately respond to a request for comment. ADVERTISEMENT Justice Initiative has offices in the North Caucasus in southern Russia, which includes Chechnya. It helps Russian citizens file cases over rights violations at the European Court of Human Rights. Security officers armed with automatic rifles raided the group’s Moscow offices in August last year. President Vladimir Putin has tightened controls on non-governmental organisations, requiring those with foreign funding to register as “foreign agents” and approving legislation that allows groups seen as “undesirable” to be outlawed. Reporting by Tom Balmforth; editing by Andrew Osborn