Dr. Spanta was speaking during the international conference of security talks in western Herat province of Afghanistan.
He said the agreement will be signed with the US on coming Tuesday, a day after the presidential inauguration.
The draft bilateral security agreement between Kabul and Washington was endorsed by majority during the consultative Loya Jirga last year. But, President Karzai refused to sign the agreeement and set new conditions for the signing of the deal.
Karzai said Washington should take practical steps to ensure peace and stability in the country and end raids on Afghan homes before he signs the agreement.
The bilateral security agreement once signed will pave the way for the signing of a similar agreement between Afghan government and NATO that will give a legal framework for the presence of US and NATO forces in Afghanistan beyond 2014.
US and NATO are planning to leave a residual force in Afghanistan to implement the Resolute Support Mission that will focus on training, advise and support of the Afghan national security forces.