Brent crude fell below $28 a barrel in Asia on Monday for the first time in more than 12 years on fears about a worsening supply glut after Western sanctions on Iran were lifted, allowing Tehran to resume oil exports.

Up to half a million barrels per day of Iranian crude could be added to already saturated markets after U.S. and European leaders ended a crippling embargo put in place over Tehran's nuclear program.

Iran needs annual foreign investment of $30-$50 billion to reach an eight percent growth target and cash in on a nuclear deal with world powers, President Hassan Rouhani said Sunday.

Laying out the budget for the next Iranian year which starts March 20, Rouhani told parliament, a day after the implementation of the historic deal, that the collapse in global oil prices meant the government had to look to abroad to boost the economy.

Share prices in the energy-rich Gulf states nosedived Sunday following the sharp decline in oil prices and the expected rise in Iranian crude exports after the lifting of sanctions.

The plunge in the first day of trading in the Muslim week also follows heavy losses in global bourses on Friday, when Gulf exchanges were closed for the weekend.

The European Central Bank is set to hold the door open for further easing at its policy meeting this week, after measures taken in December to drive eurozone inflation higher disappointed investors, analysts said.

"After disappointing markets in December, we expect the ECB to indicate at its forthcoming meeting that the door is still open to bolder policy support," said Capital Economics economist Jennifer McKeown.

Iran's intention to significantly increase oil output after the lifting of international sanctions risks more pressure on crude prices already at 12-year lows, according to analysts.

Oil prices tumbled by more than 30 percent last year and have slumped by a further 20 percent since the beginning of 2016 -- culminating in drops below $30 a barrel last week. 

Standard & Poor's announced Friday it had bumped up Iceland's credit rating by one notch to BBB+, citing progress over the easing of capital controls imposed during the 2008 banking crisis.

"The upgrade primarily reflects the further progress Iceland has achieved in resolving the issues standing in the way of capital account liberalization since June 2015," the ratings agency said in a statement.

The U.S. Patent and Trademark Office has given Cuba a green light to sell Havana Club rum in America when it lifts its embargo against the communist island, documents showed Friday.

The trademark, which was granted Wednesday, represents an end -- at least for the moment -- to a long legal battle between the two makers of the rum, Cuba and Bacardi, the latter of which produces the drink in Puerto Rico.

Amazon said Friday it has taken the first steps to begin maritime shipping operations, adding to its already vast arsenal of logistical operations.

The company confirmed to AFP that it had registered with the U.S. Federal Maritime Commission to operate via a Chinese subsidiary Beijing Century Joyo Courier Service.

Venezuela's President Nicolas Maduro decreed a state of "economic emergency" on Friday, seizing the initiative in a political standoff with the opposition in the oil-rich state.

"A state of economic emergency is declared across the whole territory of the nation" in accordance with the constitution, "for 60 days," read the decree published by the official state journal.

Ukraine on Friday launched the first cargo train to China that will bypass Russia along a new "Silk Road" meant to counter the Kremlin's most stringent trade embargo on Kiev to date.

"This is a historic event," Ukrainian Infrastructure Minister Andriy Pyvovarskiy wrote on Facebook.