London  - US President Barack Obama will make his first major foray onto the global stage Tuesday when he arrives in London for the Group of 20 (G20) summit of the world's big economic powers.

His trip comes against the backdrop of a deepening global recession with the leaders attending summit expected to agree to a major revamp of the world financial system as well as steps to ensure greater coordination between governments in combating the downturn.

Apart from marking a new era in trans-Atlantic relations, Thursday's G20 summit will also represent the first opportunity that world leaders have had to meet the new US president.

Obama is scheduled to meet with leaders of China, India Saudi Arabia - three of the world's key emerging economies - as well as Russian President Dmitry Medvedev.

After the London summit, he is to attend the 60th anniversary NATO summit to be held in Germany and France, where he is due to meet both German Chancellor Angela Merkel and French President Nicolas Sarkozy.

Later, Obama is to travel to Prague for a US-European Union summit and then on to Turkey, with the White House hoping his trip will help to lay aside the fraught relations that emerged between Washington and Europe as well as the Muslim world under US president George W Bush.

However, the build-up to Obama's departure and the London summit has been accompanied by tensions between Washington and its European allies over the White House's push for fresh fiscal measures to spur global economic growth.

Spearheaded by Merkel, Europe remains sceptical about throwing more money at the recession, arguing that it will take some time for the measures introduced to take effect and that the focus should now be on financial reform.

But none of the government chiefs attending the London summit will want to see it fail in the midst of the world's biggest financial crisis since the Great Depression.

Least of all Obama, who will to be keen to ensure his first steps on the world diplomatic stage do not end on a sour note.

So instead of new concrete budget measures to help haul the global economy onto its feet, the G20 leaders are likely to take their cue from their finance ministers' meeting this month and simple declare they will do what ever is necessary to fight the recession. (dpa)