Jan 15 (Reuters) - Iranian officials have told Syria they would now have to pay more for additional shipments of oil, which will double the price to a market rate of more than $70 a barrel, the Wall Street Journal reported on Sunday, citing people familiar with the matter.

Iran has also refused new deliveries on credit and asked Syria to pay in advance for new oil supply, WSJ said.

Reporting by Shubhendu Deshmukh in Bengaluru; Editing by Susan Fenton