THE HAGUE (AFP) - UN Secretary-General Ban Ki-moon said on Wednesday that UN inspectors needed four days to conclude a probe into chemical weapons use in Syria.

"My mandate and my responsibility at this time is to conduct a thorough and complete investigation," Ban told reporters in The Hague.

"Let them (inspectors) conclude their work for four days," he said, adding that their findings would then be analysed and the result sent to the UN Security Council.