WASHINGTON - President Donald Trump said members of the U.S. military sent to the southern border to keep out thousands in a migrant caravan would "fight back" if immigrants throw stones and suggested soldiers might open fire on the group because there's "not much difference" between a rock or gun.

In an address from the White House Thursday, just days before the midterm elections, Trump announced his administration was preparing to change the country's asylum practices and took on the thousands of migrants fleeing the dangers in Central America and heading toward the U.S. in hopes of claiming asylum.

He pointed to reports of a clash between authorities and the caravan as they moved across the Guatemalan border to Mexico. Mexico authorities said migrants attacked its agents with rocks, glass bottles and fireworks when they broke through a gate on the Mexican end but were pushed back, according to the Associated Press. It's unclear whether any Mexican authorities were injured but Guatemalan officers were hurt.

Trump said the U.S. military wouldn't accept bottles or stones being thrown at them.

"They want to throw rocks at our military, our military fights back," the president told reporters. "I told them to consider it a rifle. When they throw rocks like what they did to the Mexican military and police I say consider it a rifle."

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The president continued, saying he did not want a violent clash between the migrants, many of whom are women and children, but said the military was ready in case.

"I hope not," Trump said when asked about whether he envisions military shooting any of the migrants.

He continued, claiming members of the military were "badly hurt" by migrants armed with stones. He said any stone will be considered a "firearm because there's not much difference when you get hit in the face with a rock."

Trump has sought to make immigration a central issue in the midterm elections, where Republican control of the House and Senate are up for grabs. Critics have said Trump is playing up fears about the caravan, which is still about a month away from the U.S. border, to ramp up support from his base.

Over the weeks, Trump has threatened to shutdown the border and halt funding to countries where the caravan was passing through. The Pentagon said Wednesday it would send some 7,000 active duty troops to the border, and the president has said that deployment could expand to between 10,000 and 15,000 troops.

During his White House address, Trump said he would unveil a plan to limit claims of asylum in the United States, saying there was "rampant abuse" of the system.

But he offered no details on the proposal, which was part of a series of immigration announcements he has rolled out in the run-up to next Tuesday's elections.

Trump said people were taking advantage of the asylum process by making false claims of persecution in order to enter the country. He said many end up staying in the country and fail to show up for court proceedings to determine the validity of their asylum claims.

Trump vowed to build "tent cities" to detain asylum seekers until their court hearings.

Existing U.S. laws give people entering the country broad authority to make asylum claims. Trump did not make clear whether he would seek changes in the law but he did indicate he would be unveiling an executive order.

Contributing: David Jackson and the Associated Press