Khaleeq Ahmed, a spokesman for Hamid Karzai, the president, said on Wednesday: "After 30 years of devastation, we are starting from nothing and any move such as this helps the reconstruction of Afghanistan."
On Tuesday, Sean McCormack, the US state department spokesman, announced that Washington was ready to forgive $108 million. The sum equals Afghanistan's total official debt to the US.
"The United States calls on other creditors to provide the same 100% debt relief," McCormack said.
The debt will be cancelled through the procedures of the Paris Club, an informal group of creditor nations.
Earlier this week, Russia and Germany, other Paris club creditors, said they would cancel debts of the war-torn country.
Russia said it was ready to write off $10 billion that Afghanistan borrowed from the Soviet Union. Russia assumed Soviet liabilities and credits after the Soviet system's collapse.
Germany also announced its intention to provide 100% cancellation of Afghanistan's debt.
The debt cancellation will remove a big worry from Karzai's government, installed by the US invasion in 2001 and later winner of national elections.
Karzai is struggling to deal with an upsurge in violence in recent months.