The measures agreed to at the G20 summit in London on April 2 2009 must be introduced rapidly and in the most professional way possible, European Central Bank president Jean-Claude Trichet said.

In an interview with Il Sore 24 Ore, a transcript of which was posted on the ECB website on April 9 2009, Trichet said that the G20 meeting was a "very important turning point...in international co-operation".

Asked whether he believed that governments had been slow to introduce anti-crisis measures, Trichet said that "at the global level - and thus also the level of the euro area - they have not been quick enough to be entirely convincing in the eyes of economic agents".

"A great deal of support has been decided - in the EU, it represents 23 per cent of GDP - but it has not always been implemented in an effective manner. And this is why the measures agreed in London must be introduced quickly, rapidly and in the most professional way possible," Trichet said.

Asked to comment on the fact that markets and raw materials prices have been rising in the past few weeks, he said: "We are experiencing a market correction that is very large, very challenging and very turbulent. It is a process that is still under way.

"We have to demonstrate responsibility, at the public and the private level, and we have to be ready to deal with unexpected events, which have been a characteristic of this crisis. In short, we have to remain permanently alert," Trichet said.

On the issue of the possible nationalisation of banks, Trichet said that if state control were to prove necessary, it would be preferable "by far" that the state takes control of a bank but without changing the legal framework, meaning that the company remains governed by private law and the government is simply a shareholder.

"The credibility of the choices is also dependent on the existence of a strategy to return to a normal situation. In the same way that we, as a central bank, have to have an exit strategy from monetary policy in exceptional times, governments must think of an exit strategy from extraordinary measures of economic policy," Trichet said.

Asked to comment on the economic situation in the euro area, he said that 2009 would be a very difficult year, with a strong contraction in activity.

"Quarterly data will probably not return to positive territory before the course of 2010. We expect a gradual recovery next year, on the condition that the economic policy measures announced thus far at the international level are introduced, as I have already said, in a rapid and highly professional manner," Trichet said.

Asked about further decisions to be taken in May when the ECB Governing Council meets, Trichet confirmed that he "did not exclude that we could - in a very measured way - go down from the present level" of the main refinancing operation rate.

"As regards the deposit facility rate, I said that at 0.25 per cent it is already at an extremely low level and that I did not expect that we will change that level in the period to come.

"As regards possible further unconventional measures, I said indeed that the Governing Council will take its decision in our next monetary policy meeting in May. The Governing Council did not want to pre-empt in any respect what we may say then," Trichet said.