Oil prices on Tuesday slipped further toward six-year lows in Asia after major crude producers stressed they will maintain output levels despite an oversupply.

U.S. benchmark West Texas Intermediate (WTI) for February delivery was down 58 cents at $45.31 a barrel in afternoon trade and Brent crude for February dropped 54 cents to $46.05.

Kuwait said Tuesday that the sharp fall in world oil prices is unjustified but that the market may not improve before the second half of this year.

"Nobody can justify the drop now," Oil Minister Ali al-Omair told reporters as prices slid towards six-year lows.

President Hassan Rouhani said Tuesday that Iran would withstand the economic pain of falling oil prices, suggesting Saudi Arabia would suffer more in the long run from the current slump.

Iran has been among the oil exporting countries worst hit by a more than 50 percent slide in the price of crude in recent months, given its budget was based on sales at $100 per barrel.

The Russian ruble tumbled against the dollar and the euro for the second day in a row on Tuesday, punished as oil prices plunged further.

The ruble was worth 64.68 against the dollar and 76.43 against the euro at around 0900 GMT, down from 63.17 and 74.68 on Monday evening.

The German government managed to balance its books for the first time since 1969 in 2014 and a year ahead of target, the finance ministry said Tuesday.

Originally, the government had been penciling in a small budget deficit of 6.5 billion euros ($7.7 billion) for 2014.

The United Arab Emirates said on Tuesday that OPEC will no longer move to shore up crude prices, arguing that rising North American shale oil output needs to be curbed.

World prices have been falling since June but the pace of the slide accelerated in November when the Organisation of the Petroleum Exporting Countries (OPEC) decided to maintain its production unchanged at 30 million barrels per day.

Oil extended its "disconcerting" plunge towards six-year lows in Asia Tuesday after Wall Street giant Goldman Sachs lowered its price forecast, adding to concerns about a supply glut and weak demand.

U.S. benchmark West Texas Intermediate (WTI) for February delivery was down 82 cents at $45.25 a barrel in afternoon trade and Brent crude for February dropped 99 cents to $46.44.

The collapse of Cyprus Airways nearly two years after a financial earthquake shattered the economy has dealt a new blow to the recession-hit Mediterranean island, experts said Monday.

Cyprus is facing record unemployment of around 16 percent, according to economists who say the situation will only worsen as the national carrier's 560 staff are laid off.

Hungary has restarted gas supplies to neighboring Ukraine, Hungarian pipeline network operator FGSZ Zrt said Sunday, after suspending deliveries in September, prompting criticism from Ukraine's state-owned gas firm Naftogaz.

"I can confirm that gas delivery from Hungary to Ukraine has begun," FGSZ spokeswoman Edina Lakatos told AFP in an email.

Goldman Sachs will advise Dublin on its options for selling the state-rescued Allied Irish Banks, finance minister Michael Noonan said Monday as the government seeks to recoup taxpayers' cash.

Dublin nationalized 99.8 percent of Allied Irish Banks (AIB) in 2010 at the height of the financial crisis, pumping 20.8 billion euros into the lender.