WASHINGTON, Sept 16 — US Energy Secretary Rick Perry said today it was too soon say whether the United States would have to tap its emergency petroleum reserves following weekend attacks on Saudi Arabian oil facilities that shook global oil markets.

"We are yet a little premature in making any ... actions about whether or not the (US Strategic Petroleum Reserve) is actually going to be needed, until we get a handle on the length of time that this facility is going to be down,” Perry told CNBC in an interview from Vienna.

After Saturday’s attacks on the heart of Saudi Arabia’s oil processing that shut 5 per cent of global oil supply the kingdom has said it could bring back about a third of the shut supply today.

US President Donald Trump has said the US administration stood ready to tap the reserve if needed. The reserve holds about 645 million barrels of oil in underground caverns on the coasts of Texas and Louisiana, or about what the United States uses in a month.

The Department of Energy also said it was working with the Paris-based International Energy Agency, which coordinates energy policies of 30 industrialised countries, on whether a combined emergency release is needed.

Perry said countries in the IEA, of which the United States is a member, have more than 1.5 billion barrels of oil in reserves.

Perry said he expected a coalition of countries to come together to respond in the wake of the attacks, but gave no details about any possible action. — Reuters