Ukraine is not to join the Collective Security Treaty now, Yevgeny Marchuk, the Secretary of the National Security and Defence Council, told journalists Friday. Marchuk as an observer attended the meeting of the Committee of the Security Councils' Secretaries of six states signatory to the Collective Security Treaty - Russia, Belarus, Armenia, Kazakhstan, Kirghizia and Tajikistan. Answering the journalists' questions on Ukraine's participation in the meeting and its possible joining the Collective Security Treaty, Marchuk stressed that this issue should be solved by means of a referendum. "Ukraine is participating in the international counter-terrorist operation in Afghanistan," Marchuk said. According to him, Ukraine comes for the establishment of a legislative and international-legal basis for conducting anti-terrorist operations in other countries in the future.