Crude oil prices were up at trading start on Tuesday as rising tensions in the Middle East are posing a risk against secure oil supply from the region to the global market.
International benchmark Brent crude was trading at $72.19 per barrel at 0630 GMT with a 0.14% gain after it closed Monday at $72.09 a barrel.
American benchmark West Texas Intermediate was at $63.52 a barrel at the same time for a 0.17% increase after ending the previous session at $63.41 per barrel.
U.S. President Donald Trump said Monday that Iran "will be met with great force," if it makes a move against the U.S.
"If Iran wants to fight, that will be the official end of Iran. Never threaten the United States again!" Trump wrote on Twitter on Sunday.
Iraqi capital Baghdad's Green Zone was attacked on Sunday, which added to the increasing tensions in the Middle East region.
Saudi Arabia's two oil tankers off the coast of the United Arab Emirates were attacked on May 12, and this was followed by a drone attack on two oil-pumping stations in Saudi Arabia on May 14.
The escalation in tensions came after Washington tightened sanctions on Tehran on May 2 with the aim of reducing Iranian exports down to zero, and with the increased presence of the U.S. military in the Gulf.
By Ovunc Kutlu