Immigration and Customs Enforcement Director John Morton said Tuesday his agency deported nearly 400,000 people during the fiscal year that ended in September, the largest number ever.
He said about 55 percent of those deported had felony or misdemeanor convictions. Officials said the number of those convicted of crimes was up 89 percent from 2008.
Authorities could not immediately say how many of those crimes related to re-entering the U.S. after being deported. Individuals can be convicted of a felony for returning to the U.S. or being found in the U.S. after they were deported.
Among the 396,906 individuals deported were more than 1,000 convicted of homicide. About 5,800 were sexual offenders, and about 80,000 people were convicted of drug related crimes or driving under the influence. Last year, the total was roughly 393,000.
"This comes down to focusing our resources as best we can on our priorities," Morton said. "We continue to hope for comprehensive immigration reform at a national level, working with the Congress, but in the meantime, we work with the resources we have, under the laws we have."
The announcement comes as the Obama administration has sought to address critics on both sides of the immigration debate.
Immigration advocates complain law enforcement officials are spending too much of their scarce resources rounding up families living illegally in the country who otherwise are law-abiding.
Others say the administration isn't doing enough to stop the flow of illegal immigration and protect Americans from potential foreign terrorists and other criminals.
Department of Homeland Security Secretary Janet Napolitano has said the agency is focusing its resources on criminals, recent border crossers, those who repeatedly cross the border and those people the department considers fugitives.
Authorities say two-thirds of those deported last year recently crossed the border or had done so repeatedly.
But House Judiciary Chairman U.S. Rep. Lamar Smith, R-Texas, an outspoken opponent of Obama administration's immigration policies, called the ICE numbers inflated.
He argued they include people who voluntarily agree to leave the country with no penalties and can easily return to the U.S., especially along the border.
In a statement, Smith added that under the Obama administration, worksite enforcement has dropped 70 percent.
"We could free up millions of jobs for citizens and legal immigrants if we simply enforced our immigration laws," he added.
In 2009, the administration shifted from high-profile workplace sweeps to less attention-grabbing auditing of I-9 forms -- documents used to verify that employees are legally eligible to work in the U.S. The department says the shift better focuses resources on the employers who draw in illegal workers to the country.
Susana Barciela, policy director for Miami-based Americans for Immigration Justice, expressed concerns about the numbers.
"We are worried because many of the people who are being deported have committed minor crimes," she said.
She mentioned cases in which immigrants were detained and convicted of driving with broken tail lights, polarized windows or expired driver's licenses, common among illegal immigrants who are unable to legally obtain or renew their licenses and then are deported.