Work in Afghanistan's security forces is considered low-paid and dangerous
The Afghan government and its international partners have agreed to increase the country's security forces by more than 100,000 within two years.
A panel of officials from Afghanistan, the UN and countries contributing troops want an army of more than 170,000 and a police force of 134,000.
The move comes ahead of a conference in London next week which aims to boost international support for Afghanistan.
But Afghan security forces have long been battling high rates of desertion.
The Joint Coordination and Monitoring Board agreed to increase the size of the Afghan National Army from the current figure of about 97,000 to 171,600 by the end of 2011, the Associated Press news agency reported, quoting officials.
The Afghan National Police would be be boosted from about 94,000 today to 134,000 under the plan, it said.
Authorities say they are introducing incentives to bring down the rate of desertion. Work in Afghanistan's security forces is considered low-paid and dangerous, particularly for those battling insurgents in the south and east of the country.
The board set a long-term goal of expanding the Afghan security force to 240,000 soldiers and 160,000 police within five years.
But officials said that figure may not be necessary if the US-led campaign against the Taliban succeeds in crippling the insurgency, AP reported.
In his inauguration speech, while being sworn in for the second term in November, President Hamid Karzai said the strength of Afghan security forces had to be bolstered and the role of international forces reduced.
But Mr Karzai warned that it would be a long time before Afghanistan would be able to pay the cost of maintaining its own army and police force.
The president said it would take 15 years before the country was able to pay for the cost of its own security forces and appealed to the US and the international community to continue funding them.
Last year, US President Barack Obama announced that he would be sending 30,000 more troops to Afghanistan.
Nato allies agreed to send at least 7,000 extra troops to support the US surge in Afghanistan.