Prime Minister Shinzo Abe and British Prime Minister David Cameron agreed Wednesday to call for more humanitarian aid for war-torn Syria, a senior Japanese official said.

Cameron was quoted as telling Abe in a telephone conversation that the situation in Syria should be taken up at the two-day summit of the Group of 20 nations starting Thursday in St. Petersburg.

Abe, who arrived in the Russian city Wednesday, told Cameron that Japan will work harder to help refugees from the two-year-old civil war, the official said. They did not discuss the possibility of the United States taking military action against the regime of President Bashar Assad in reaction to its alleged use of chemical weapons against civilians, the official said.