“You are going to see a sustained focus on criminal offenders from this agency,” ICE Director John Morton told reporters. “These are not the kind of people we want walking our streets.”

Authorities arrested 2,901 people in the weeklong “Cross Check” operation, described by the agency as the biggest of its kind, officials said. Arrests were made in all 50 US states and in four US territories, officials said.

Those arrested included citizens of Mexico, the Dominican Republic, Panama, Honduras and Nigeria, officials said.

All those arrested had previously been convicted of crimes in the United States and will be deported, officials said. More than 1,600 had felony convictions, including manslaughter, attempted murder and drug trafficking, they added. Those arrested also included gang members and sex offenders.

At least 1,282 of those arrested had multiple criminal convictions, officials said.

Morton estimated that about a million illegal immigrants who have criminal convictions and are subject to removal are still in the United States. The agency said it deports about 390,000 people a year, about half of them convicted criminals.

Illegal immigration is a hot political issue in the United States. More than 11 million illegal immigrants live and work in the United States, according to the Pew Hispanic Center.

States including Arizona and Georgia have tried to enact their own laws cracking down on illegal immigration, arguing that the federal government has done too little to stop it.

The White House said in August that the US government will review its deportation caseload to keep low-priority cases from resulting in removal.

Democratic congressional leaders praised the move and said it would ease the way for individuals who came to the United States illegally as children and have already spent years in the country to stay and work legally.

Texas Governor Rick Perry, front-runner in the race for the Republican presidential nomination to face President Barack Obama in the November 2012 election, has been accused by members of his own party for not being tough enough on illegal immigration.

Rivals have blasted Perry’s state policy allowing children of illegal immigrants living in Texas to pay the same cheaper in-state college tuition rates that other Texas children pay.