A woman waits with others being processed by Mexican authorities in Nogales, Sonora, after being deported from the U.S. Mexico has warned its citizens to use extreme caution if visiting Arizona because of its tough new immigration law, which has yet to take effect. GREGORY BULL / THE ASSOCIATED PRESS

WASHINGTON - An emerging immigration proposal by three Democratic senators calls for more federal enforcement agents and other border security-tightening benchmarks before illegal immigrants could become legal U.S. residents.

Those goals "must be met before action can be taken to adjust the status of people already in the United States illegally," according to a copy of the draft legislation, obtained Wednesday by The Associated Press, that Sens. Harry Reid of Nevada, Chuck Schumer of New York and Robert Menendez of New Jersey are developing.

Arizona's new strict immigration law has led to renewed demands for Congress to pass a comprehensive immigration bill. Reid, the Senate majority leader, recently said he was committed to taking up immigration this election year, but also backed away from the possibility of addressing the divisive issue before climate change. And the issue has failed to attract Republican interest in a bill so far this session.

Spokesmen for the three senators declined to comment on the proposal.

On his way back from a trip to the Midwest, President Obama said that, although a lot of work needs to be done on immigration, "there may not be an appetite" in Congress to deal with another hot-button issue immediately after grueling fights over health care and financial regulation.

The president cited work to be done on energy and upcoming midterm elections, telling reporters aboard Air Force One he didn't want to do something "just for the sake of politics." Rather, he said, he wanted to come up with solutions to immigration that will have broad support from the American people.

Sen. Lindsey Graham, who has worked with Schumer on an immigration bill, has balked at moving ahead this year. Graham, R-S.C., said Tuesday that drug violence along the border with Mexico is evidence that the border is not secure. He said immigration reform would fail if brought up this year.

Democrats have been unable so far to get a second Republican to join Graham in writing a bipartisan immigration bill. The outline of the immigration proposal issued Wednesday is an attempt to persuade some Republicans to change their minds.

The benchmarks in the proposal include additional Border Patrol officers and Immigration and Customs Enforcement agents to combat smuggling; more ICE inspectors at work sites; an increased number of ICE officers assigned to detect fraudulent documents and find better ways to determine fakes; more personnel to check for contraband at ports of entry; additional resources to prosecute drug and human smugglers and illegal border crossers, and for deportations.

An outline of the proposal does not specify the additional agents or resources required to meet the benchmarks. It does suggest a two-phase system for legalizing people who are in the U.S. illegally.

Before the benchmarks are met, the Homeland Security Department could begin registering, fingerprinting and screening illegal immigrants, and considering them for an interim legal status. That would allow them to work in the U.S. and travel outside it.

Such immigrants could start applying for legal permanent residence, eight years after backlogs of visas for people coming to the U.S. legally have been cleared and after the security benchmarks are met. They also must show they have basic citizenship and English skills, have paid all taxes, fees and civil penalties and registered for the military draft.