Washington will announce on Monday a massive aid package to Afghanistan, which it hopes will assist the war-torn country get back on its feet after 12 years of playing host to foreign troops, Reuters has learned.

The US Agency for International Development (USAID) will announce three new development programs worth almost $300 million to wean Afghanistan off its 'war economy,' which is heavily subsidized today by opium exports – a trade that had been practically squashed while the country was under Taliban rule.

Under the USAID initiative, $125 million will go to reviving Afghanistan's food and farm sector, and another $77 million to opening up the country to greater international trade and investment. The last program, valued at about $100 million, would seek to assist Afghanistan’s educational system.

"The question is, what can we do now to make sure Afghanistan is as healthy, sustainable and feasible as possible going forward," Larry Sampler, the agency's chief official for Afghanistan and Pakistan, told Reuters.

Sampler said the three-stage cash injections would help buffer Afghanistan as the war economy winds down, together with the foreign military operation.

The promise of a cash handout by USAID comes as Washington is trying to get Afghan President Hamid Karzai to sign a bilateral security pact needed to keep US troops there after this year.

Karzai has thus far refused to sign over US demands that its troops receive immunity from Afghan courts in any future criminal cases.

• A Permanent Economic Emergency