The US should ratify an extradition treaty which the UK has already agreed to "as soon as possible", the country's attorney general has said.
The matter is 'in the hands' of the Senate, Mr Gonzales said
Alberto Gonzales told BBC Radio 4's World at One that getting such measures through the Senate "takes time".
Critics are unhappy that, although the UK parliament has ratified the treaty, the Senate has not.
This means American prosecutors find it easier to extradite suspects from the UK than vice versa, they say.
'Done its job'
Parliament agreed to the Extradition Act, which is intended to speed up the legal processes involved, in 2003.
Mr Gonzales, who is on a trip to Britain, said: "I would like to see it ratified as quickly as possible as well. I conveyed that to the British government officials on this visit.
"The executive branch of the United States government has done its job. It is now in the hands of the Congress of the United States Senate.
"People need to understand that, as a general matter, ratification of treaties takes time in our country."
Last month, three British bankers lost their High Court battle against extradition to the US to face charges over the collapse of the energy company Enron.
Lord Justice Laws ruled that the case was "perfectly properly triable" in the US.
The case has generated criticism of extradition laws which do not require the US to provide "prima facie" or solid evidence of wrongdoing to extradite a UK citizen.
Britain must still provide the US with evidence of "probable cause" if it wishes to extradite someone from America.
The men will now try to take their battle to the House of Lords.
Home Secretary Charles Clarke told the BBC the government was "working very hard" to persuade the US to ratify the treaty.
He said: "We'll continue to make our case very forcibly. I'm sure the case is moving our way and I'm sure the Senate will ratify the treaty and I think it's important that they do."
Conservative MP Boris Johnson has said he is concerned over a "serious imbalance and asymmetry".
Sir Menzies Campbell, the Liberal Democrat leader, said the government had failed to stand up for British interests.