* NATO discusses Syria, no alliance response planned for now
* Alliance to keep situation in Syria under "close review"
NATO Secretary-General Anders Fogh Rasmussen said on Wednesday information from a variety of sources pointed to President Bashar al-Assad's forces being responsible for the use of chemical weapons in Syria.
Speaking after a meeting of NATO ambassadors in Brussels, Rasmussen said any use of such weapons was "unacceptable and cannot go unanswered", although he did not suggest any response.
"This is a clear breach of long-standing international norms and practice... Those responsible must be held accountable," he said in a statement.
Western powers are weighing up options for possible military strikes against Syria following a suspected chemical weapons attack on a Damascus suburb last week that killed hundreds of civilians.
Rasmussen said the military alliance would keep the situation in Syria under "close review". But a NATO diplomat said there was no discussion during Wednesday's meeting of a potential role for the alliance in any actions for now.
NATO conducted air strikes in Libya in 2011, mandated by the U.N. Security Council to protect civilians during a violent crackdown against rebels opposing Muammar Gaddafi.