A tough new immigration law in Arizona is drawing plenty of enemies who hope to kill it, including U.S. President Barack Obama, Democratic lawmakers and the Mexican government.

The law is expected to go into effect in July and will require police to question people about their immigrant status if they suspect they are in Arizona illegally.

Immigrants unable to produce documents showing they are allowed to be in the United States could be arrested, jailed for up to six months and fined $2,500 US, a significant escalation of the current federal punishment of deportation.

On Tuesday, Obama warned that the law targets people who look like they might be illegal immigrants, specifically Hispanics.

"Now suddenly if you don't have your papers, and you took your kid out to get ice cream, you're going to get harassed — that's something that could potentially happen," Obama said of the Arizona measure. "That's not the right way to go."

He is pleading with Republicans to join with Democrats to find a permanent solution to the country's broken immigration system.

"I will bring the majority of Democrats to the table in getting this done," Obama said in response to a question at a town hall in south-central Iowa. "But I've got to have some help from the other side."

Democrats, Mexico react

Some Republicans, including Congressman Ted Poe of Texas, accuse the Obama administration of doing more to secure the borders of foreign countries than its own and called for immediate action to reverse that.

"We want the National Guard to be armed and defend themselves if necessary and to assist the border patrol and local law enforcement," Poe told reporters in Washington, D.C., on Wednesday.

Republican Gov. Jan Brewer, who signed the bill on Friday, said Arizona must act because Washington had failed to stop the flow of illegal immigrants and drugs from Mexico. The state is home to an estimated 460,000 illegal immigrants, is the nation's busiest gateway for people slipping into the country.

'If we continue to let this go unattended, what happened in Arizona will be replicated in other parts of the country.' —Congressman Raul Grijalva, of Arizona, who opposed the law

But Democratic Congressman Raul Grijalva of Arizona said Wednesday that Republicans are using the issue to divide people.

"We're here to say it's time to deal with comprehensive reform realistically and begin the process of healing this country," Grijalva told reporters outside Capitol Hill.

"If we continue to let this go unattended, what happened in Arizona will be replicated in other parts of the country and the fight we will have in Arizona will become everybody else's fight."

Rallies have been held across the country to protest against the bill, and on Monday, vandals smeared refried beans in the shape of swastikas on the state Capitol's windows.

Mexico has warned the proposal could affect cross-border relations. On Thursday, Mexico's senate unanimously passed a resolution urging Brewer to veto the law. Mexican President Felipe Calderon said the law is discriminatory and warned that trade and political ties with Arizona will be seriously strained by the crackdown.

Obama has given no firm timeline for change, saying only he hoped to get a deal done "sometime soon." That is a politically vague timetable in an election year with a shrinking window for legislative action.

With files from The Associated Press