Oxfam says that some 670,000 people have left Syria since the crisis began in March 2011 but numbers have risen recently. In Jordan alone, the number of people crossing daily trebled in the past week.
The cold weather has seen an increase in the number of those suffering respiratory infections and pneumonia, according to the aid agency, which is distributing mattresses, blankets, heaters and gas oil to help new arrivals.
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A mild night and another misty, grey start in places in the morning.
John Kelly said he was "broken hearted" by the criticism, adding the president had expressed his condolences "the best way that he could".
A survey by ITV News found Tory activists are surprisingly supportive of the Prime Minister, despite the result of the General Election.