(REUTERS) -- Brent crude rose above $112 on Friday as Supreme Leader Ayatollah Ali Khamenei warned that the Iran would retaliate over an oil embargo "at the right time".
Khamenei said Tehran would not yield to international pressure to abandon its nuclear program.
"Sanctions will not have any impact on our determination to continue our nuclear course ... In response to threats of oil embargo and war, we have our own threats to impose at the right time," Khamenei told worshippers in a speech broadcast live on state television.
By 4:46 a.m. ET, front-month Brent crude was 33 cents up at $112.40 a barrel, gaining for a fourth consecutive day. U.S. crude rose by 50 cents to $96.86 a barrel, reversing five straight sessions of losses.
"This newsflow should continue to build a Brent premium, and could widen the Brent-WTI ( U.S. crude ) spread," Commerzbank oil analyst Carsten Fritsch said.
The spread between the two benchmark crudes stood at $15.54 a barrel by the same time, having widened the previous session to above $16.
The Washington Post reported that U.S. Defense Secretary Leon Panetta was concerned about the increased likelihood Israel would launch an attack as early as April. CNN said it confirmed the report, citing a senior Obama administration official, who declined to be identified.
Oil gains were however capped by caution ahead of key U.S. jobs data, and as Greece inched towards a deal with its creditors.
Investors will scrutinize the U.S. employment report, mindful of an anticipated slowdown in first quarter U.S. economic growth affecting oil demand from the world's top consumer.
U.S. non-farm payrolls were forecast to rise by 150,000 after a 200,000 increase in December, according to a Reuters survey, with the unemployment rate seen static at 8.5 percent.
"The jobless figures could have an impact on oil prices depending on outcome via risk appetite, but these numbers are notoriously volatile so there is room for heightened volatility in the afternoon," Fritsch added.
