Oil climbed above US$143 a barrel Friday in Asia, boosted by concerns over possible disruption to tight global supplies amid tensions over Iran's launch of test missiles and the possible renewal of oil-related violence in Nigeria. "There's always a fear premium in pricing. The tensions in Iran and the threat of supply disruption will help support oil prices," said Jeff Brown, managing director of FACTS Global Energy in Singapore. Late afternoon in Singapore, light, sweet crude for August delivery was up US$1.99 at US$143.64 a barrel in Asian electronic trading on the New York Mercantile Exchange. The contract rose US$5.60 in the overnight floor session to US$141.65 a barrel - after losing nearly US$10 on Monday and Tuesday and then gaining a penny on Wednesday. A day after Iran tested a missile capable of reaching Israel, Secretary of State Condoleezza Rice warned the oil-producing nation that the United States will defend its allies. Iran then responded with another missile launch, drawing buyers back to jittery energy markets.