While security in the country's provinces is uneven, Atmar told CNN Friday he was confident the Taliban and other insurgents could be defeated.
"We have to show the resolve, the determination and the ability to make decisions quickly," he said.
His remarks came as U.S. President Barack Obama neared announcing his decision on whether to send up to 40,000 additional troops to Afghanistan. The president has been discussing next steps in the U.S. strategy for Afghanistan, complicated by a disputed election and reports of a government rife with corruption.
Atmar said Karzai has made cleaning up his government a top priority during his second five-year presidential term. The minister said a major crimes task force, a general prosecutor and a special anti-corruption court will be named.
"The government has always been committed," Atmar told CNN. "The question has not been the deficit of willpower, the question has always been the resources and an agreed program and priorities."
Disputing Atmar's position was former presidential candidate and finance minister Ashraf Ghani, who said the government has become a "looting machine."
Ghani said the new government must appoint people of integrity and judgment.
"Without government positions they are nothing," Ghani said of corrupt officials. "As long as they are in control of the government, they will turn it into a force that is a threat to both the international security forces and to the Afghan people."