Chancellor Gordon Brown has told European Union finance ministers they must step up efforts to seize terrorist assets in the wake of the London bombs.
Tony Blair signs the book of condolences
He predicted there will be continuing problems if some countries fail to cut off terrorists' supply of money.
Mr Brown said he wanted the issue discussed at the World Bank and IMF.
"Just as there will be no safe haven for those who perpetrate terrorism, there will be no hiding place for those who finance terrorism," he said.
A plan to co-ordinate European anti-terror efforts was agreed after last year's Madrid train bombings, but Mr Brown now wants it to be implemented immediately.
He said many countries had invested a great deal in systems to help track down sources of terrorist finance.
The UK has frozen 45 different bank accounts - containing a total of £377,200 - since 11 September 2001.
EU PROPOSALS AFTER MADRID BOMBINGS
Monitoring bank transactions in "real time"
Proposed appointment of EU "counter-terrorism tsar"
Easier exchange of information between European law enforcement agencies
Better databases on control of weapons and information on terrorist suspects
Proposed obligatory storing of all telephone and communication data within the EU for specific periods
Other European countries, as well as America, had taken similar action, said Mr Brown.
"But it's important to realise that you're only as strong as your weakest link," he argued.
"Where there are countries that are not taking action to cut off the sources of terrorist finance, we will clearly have continuing problems."
Help would be available for other countries, said Mr Brown, but he did not say whether or not there might be sanctions against those failing to take action.
The chancellor said the European action plan agreed last year needed to be implemented as soon as possible.
"Across Europe we will act as one to send a message to terrorism that while lives have ended, the cause for justice never dies," he said.
"And we will show at every stage that because we hold steadfast to enduring ideals of freedom and justice, terrorism will always be defeated by democracy."
Among the measures in the EU action plan he wants pushed through are:
- Ensuring all member states can take action nationally to freeze terrorist assets - EU-wide mechanisms cannot currently be used to freeze accounts of EU citizens
- Making it compulsory for wire transfers of money to be accompanied by information about the identity of the sender
- Updating the EU money laundering rules to meet international standards
- Completing the European Commission-sponsored review of EU structures on tackling terrorists' finance
- Introducing a code of conduct to prevent abuse of charities by terrorists.
London's transport network was attacked with four bombs on Thursday. The blasts, on three packed Tube trains and a double-decker bus, killed at least 52 people and injured more than 700.
A young man is overcome by emotion outside King's Cross station
On Wednesday, Home Secretary Charles Clarke will chair an emergency meeting with his European counterparts on co-operation on counter-terrorism operations.
Mr Clarke wants to force telephone and internet service firms across Europe to keep records of all private telephone calls, text messages and e-mails so they can be passed on to the police if necessary.
Foreign Secretary Jack Straw pressed for the moves when he met MEPs in Brussels on Tuesday.
Fears about the costs had been exaggerated, said Mr Straw, but it was a price worth paying to save lives.