U.S. President Barack Obama will unveil new Afghan strategy through an address to the nation next Tuesday evening from West Point military academy, N.Y., the White House said on Wednesday.

"The president will address the nation on Tuesday at 8:00 pm eastern time (0100 GMT Wednesday) from the military academy at West Point on Afghanistan," White House spokesman Robert Gibbs told reporters.

He stressed that the Afghan war, which is in its 9th year, won't last "another eight or nine years."

Gibbs added that the president will meet members of the Congress before delivering the address.

Obama said Tuesday that he will announce his decision on a buildup of U.S. forces in Afghanistan "shortly" and it is his intention to "finish the job" in that country.

Without detailing his pending decision, the president predicted that the American public will be "extremely supportive" of the decision.

Obama also said decision will also include civilian and diplomatic efforts.

As the public is turning negative toward the Afghan war and his fellow Democrats are increasingly vocal in their opposition to a troop buildup in Afghanistan, the incoming decision is regarded as one of the most critical moment to shape his presidency.

Obama ordered to send 21,000 additional troops to Afghanistan in March and U.S. troop levels there has grown to 68,000.

However, as the situation in Afghanistan deteriorates, Stanley McChrystal, the top U.S. commander in Afghanistan, has been calling for 40,000 more troops since August to quell the insurgency led by Taliban.

Obama has held 10 sessions with his war council on Afghan strategy since then and weighed several options for bolstering the American contingent, ranging from sending 15,000 troops to sending the 40,000 McChrystal requested.

The last such meeting was held on Monday.

Pentagon officials said there has been no final word on the president's decision, but planners have been tasked with preparing to send 34,000 additional American troops into battle with the expectation that is the number Obama is leaning toward approving.

Meanwhile, Obama aides were quoted by the New York Times as saying Wednesday that the troop increase would most likely be slightly below 30,000.