Obama is also requesting $350m in new funding to increase security along the US-Mexico border and to combat drug gangs, and another $400m in counter-insurgency aid to Pakistan.
The US president's request, which includes money to send thousands of extra troops to Afghanistan, would push the cost of the two wars to almost $1 trillion since the September 11, 2001 attacks against the US, according to the Congressional Research Service.
However, the White House acknowledged that Obama had been critical of similar legislation used by the administration of George Bush, his predecessor, to fund the wars.
"This will be the last supplemental for Iraq and Afghanistan. The process by which this has been funded over the course of the past many years, the president has discussed and will change," said Robert Gibbs, the White House spokesman.
"This funding will do two things: it will prolong our occupation of Iraq ... and expand our military presence in Afghanistan indefinitely"
Democrat in congress
The Pentagon is now set to receive $142bn in war funding for the budget year ending September 30.
Most Democrats and Republicans are likely to support the request but those opposed to the wars said Obama needed to do more to end the military operations in both countries.
"This funding will do two things: it will prolong our occupation of Iraq through at least the end of 2011, and it will deepen and expand our military presence in Afghanistan indefinitely," said Lynn Woolsey, a Democratic congresswoman from California.
"Instead of attempting to find military solutions to the problems we face in Iraq and Afghanistan, President Obama must fundamentally change the mission in both countries to focus on promoting reconciliation, economic development, humanitarian aid, and regional diplomatic efforts," she said.