WASHINGTON - US President Barack Obama is preparing for unveiling a new job plan after his summer vacation, the White House said on Monday.

The plan will be unveiled on September5, when the president travels to Detroit, Michigan, to give a speech at the Labor Day event sponsored by the Metro Detroit Central Labor Council, the White House said in a statement.

During his ongoing vacation at Martha Vineyard, Massachusetts, Obama met one of his key economic advisors and placed phone calls to investor Warren Buffett and Ford CEO Alan Mulally.

A spokesman says Obama talked to Buffett and Mulally about possible measures to spur investment and increase growth, as well as ways of reducing America's long-term debt.

It is expected that Obama will announce proposals to boost the economy, including payroll tax reduction extension, aid to the unemployed and establishment of an infrastructure investment fund.