People are losing hope because of the recession, Prime Minister Gordon Brown said as he set out his aim to secure redoubled international efforts to ease the crisis.
In a podcast on the Downing Street website he warned fellow leaders, ahead of next week's G20 meeting in the US, that it was not time to "switch off the life support".
The PM is looking to appearances on the world stage - he will be at the United Nations General Assembly in New York before the Pittsburgh gathering - for a badly needed lift.
He said his priority for the meetings was "entrenching our recovery and securing sustainable growth" alongside tackling terrorism, climate change, global poverty and nuclear proliferation.
The public message was recorded as an audio podcast, unlike the much-mocked video issued in a bid to reassure the public that Mr Brown was acting to deal with the MPs' expenses scandal.
Critics were alarmed by the PM's series of toothy smiles and Cabinet member Hazel Blears said such videos were no substitute for knocking on doors.
Downing Street said the voice-only recording was the first of a series that had been likened to the famous "Fireside Chat" radio addresses by US President Franklin D Roosevelt in the 1930s-40s.
In it Mr Brown said: "Now is not the time to lose our focus on the economy. We must not switch off the life support. People are still losing their jobs, their homes and - in some cases - their hope. And we must not fail them.
"Instead this is the time to redouble our efforts and I have proposed a new global compact for growth, jobs and prosperity to be shared across the world."
Read More
He went on: "Leadership, vision and courage are required. It will not be easy. Tough negotiations lie ahead. But be clear - my priorities will be ensuring that people's jobs are protected and created, that the recovery happens and that we build a safer, fairer and greener Britain."
