UN leader Ban Ki-moon on Thursday renewed an "urgent call" for Syria to let inspectors into the country after the United States said government forces had probably used chemical weapons.
"The secretary general has consistently urged the Syrian authorities to provide full and unfettered access to the team. He renews this urgent call today," said UN spokesman Martin Nesirky.
"The fact-finding team is on stand-by and ready to deploy in 24-48 hours," the spokesman added, following the US administration's claims that the Syrian government has probably "used chemical weapons on a small scale."
Syria asked for a UN investigation but has since refused to let a UN team waiting in the region into the country. President Bashar al-Assad's government only wants its claims that opposition rebels used chemical arms to be investigated. Ban has said the team should also look into opposition claims.
Ban has noted the US claims and "takes seriously the assessment presented," said Nesirky. "However, the United Nations is not in a position to comment on assessments based on national intelligence information."
Senior UN officials have been in contact with US authorities, the spokesman said.
The UN team proposed by Ban is led by Ake Sellstrom, a Swedish expert who was part of UN inquiries in Iraq in the 1990s.