(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.

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U.S. jobless claims: link.reuters.com/pyj46s

Crude imports, exposure to Iran: link.reuters.com/dab65s

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DEMAND OUTLOOK

While job growth has quickened, U.S. employment remains about 6.1 million below its pre-recession level. There are no jobs for three out of every four unemployed people and 23.7 million Americans are either out of work or underemployed.

Financial markets are operating in a 'holding pattern' ahead of what is the economic equivalent of the Super Bowl, that being U.S. employment figures, Tim Waterer, senior FX dealer at CMC Markets, said in a report. A healthy U.S. jobs result would serve to justify the optimism displayed in financial markets thus far in 2012.

The employment numbers follow a more-than-expected slide in new claims for unemployment benefits in the United States last week, pointing to further healing of the battered jobs market.

Jobless claims have zig-zagged in the last few weeks, but the trend -- reinforced by the latest drop -- suggests employers have grown less eager to lay off workers, offering hope they could also step up hiring.

Oil investors also remain worried about Europe's debt crisis worsening and hurting the global economy. The euro zone's finance ministers aim to agree a second financing package for Greece on Monday, and help contain the two-year old crisis.

Commerzbank Unemployment Israel Crude oil