LONDON, England (CNN) -- The European Union has agreed to freeze the overseas assets of Iran's Bank Melli, British Prime Minister Gordon Brown said Monday, but a spokeswoman for the EU's foreign policy chief said no decision had been reached.
A spokesman for the British Foreign Office said there are "technical steps to be put into place," and "the action is likely to come into effect in the next few days." He could not explain the discrepancy coming from the E.U.
Brown said at a news conference Monday with U.S. President Bush that the sanctions were in the works.
"We will take action today that will freeze the overseas assets of the biggest bank in Iran, the bank Melli," Brown said.
Brown said new measures against Iran would be continued if the Islamic regime failed to address concerns over its nuclear ambitions.
"Action will start today in new phase of sanctions on oil and gas. We will take any necessary action so that Iran is aware of the choice it needs to make," Brown said.
But a spokeswoman for European Union foreign policy chief Javier Solana told CNN the 27-member bloc had not imposed restrictions on the Iranian bank.
"Today there was no decision on Bank Melli," Cristina Gallach said in an e-mail. "I cannot say to you when a decision on deepening further sanctions can be taken."
The British Foreign Office was not able to explain the discrepancy.
Solana visited Iran on Saturday and briefed EU foreign ministers Monday about his trip. He urged Iran on Saturday to guarantee the "peaceful nature" of its nuclear program to get cooperation and support from the EU.
Iran says its nuclear program is for peaceful purposes. But it has refused to meet U.N. Security Council demands to halt its nuclear fuel program, and the International Atomic Energy Agency reported in May that Tehran had not provided critical information that would support its position.
The United States imposed sanctions on Bank Melli and two other top Iranian financial institutions -- Bank Mellat, and Bank Saderat -- in October 2007.
Bush said Monday he has not ruled out the use of force to end Iran's suspected nuclear weapons program, but added that he preferred to resolve the dispute diplomatically.
At the morning news conference Brown also announced additional troops for Afghanistan. Watch George W. Bush meet with Gordon Brown »
Britain will increase its presence in Afghanistan from 7,800 troops to 8,030 by next spring, UK Defense Secretary Des Browne later told British lawmakers.
In his announcement to the House of Commons, Browne admitted the 230 additional troops "does not in proportionate terms represent a very significant increase."
"It does mean our mission is expanding," Browne said. "It means we are taking the steps necessary to take our mission forward as effectively as we can."
The additional forces will join Britain's existing troop presence in the southern Afghanistan province of Helmand, where allied forces are battling a resurgent Taliban.
The prime minister also ruled out any early withdrawal of British troops from Iraq -- a move that would upset the United States -- insisting forces would not be "traded" between Iraq and Afghanistan.
Bush, in Britain for the last leg of what is seen as his farewell tour of Europe before leaving the White House next year, praised Brown's commitment to Iraq, describing him as a "good partner."
Before their meeting, U.S. officials were forced to deny a rift between Brown and Bush over troops withdrawals from Iraq after a newspaper reported that the U.S. president was expected to urge the prime minister not to set a timetable.
Asked if he "got it wrong" on Iraq, Bush said: "History will judge the tactics.... Removing Saddam Hussein was not wrong. It was the right thing to do ... for 25 million Iraqis."
Bush and Brown said they talked about Zimbabwe. Brown condemned what he said was a "criminal cabal" that "threatens to make a mockery of free and fair elections.
He called on Zimbabwean officials to accept international observers to monitor the June 27 presidential runoff election pitting long-time President Robert Mugabe against opposition candidate Morgan Tsvangirai.
Bush ended the European tour in Northern Ireland where he met First Minister Peter Robinson and his deputy Martin McGuinness.
Before arriving in Britain, Bush met Saturday with French president Nicolas Sarkozy, where talks also focused on Iran.
During his tour, which has called in at Slovenia, Germany, Italy and France, Bush has urged Europeans to stand firm with the United States as it seeks to transform the Middle East.