Britain has 'directly' warned Assad of immediate response if Syria uses chemical weapons "The possible use of chemical weapons would be completely unacceptable for the whole international community," he said. If anybody resorts to these terrible weapons, then I would expect an immediate reaction. Turkey's request for Nato to deploy the Patriot anti-missile batteries came after intelligence assessments that Syria was contemplating using ballistic missiles, potentially armed with chemical warheads. Syrian stockpiles of chemical weapons are a matter of great concern. We know that Syria possesses missiles. We know they have chemical weapons and this is also the reason why it is necessary to ensure effective defence and protection of our ally Turkey," the Nato secretary-general said. Nato's declaration follows Barack Obama's warning of "consequences" should Syria's chemical weapon stockpiles be used by the regime in its bitter civil war with rebels. "I want to make it absolutely clear to Assad and anyone who is under his command... if you make the tragic mistake of using these weapons there will be consequences and you will be held accountable," the US president said. Mr Hague said that Britain was supporting the Nato missile deployment "to show solidarity with Turkey." I have made it clear that we will support the deployment of Patriot missiles in Turkey. I think it will send an important message to the Syrian regime," he said. The West is hardening its response to the conflict in Syria and the United Nations today announced it is pulling "all non-essential international staff" out of the country. Nato has stressed that under current operational planning the Patriot missiles will not be used to escalate a military response to the Assad regime but the decision comes as the West seriously contemplates further measures to aid Syrian rebels. The purpose is to protect the Turkish population and territory against missile attacks. That is its specific purpose," said Mr Rasmussen. It would in no way support a no-fly zone or any offensive operation. The Patriot missiles will be supplied by Germany, The Netherlands and the US and deployment is not expected immediately. It is expected that at least six Patriot batteries, with some 300-400 troops to protect them, will be deployed in support of Turkey on its border with Syria in the New Year. "When exactly that will happen will depend on a number of practical issues that will be sorted out in the near future... within weeks," said Mr Rasmussen. On Monday, Russia, Syria's staunchest international ally, warned against the Nato deployment.