MIAMI, United States (AFP) — Former president Barack Obama on Friday decried as a “political stunt” Donald Trump’s plan to send thousands of US soldiers to the Mexican border to block migrants from entering the country.

In a rousing speech to a Miami crowd as he campaigned for fellow Democrats ahead of next week’s midterm elections, Obama said the Republican administration was “even taking our brave troops away from their families for a political stunt at the border.”

Trump, who has placed immigration at the heart of his party’s election effort, has persistently attacked the caravan of Central American migrants, denouncing it as a potential “invasion.”

Trump announced earlier this week that he would send thousands of troops to the border to beef up national defences at the border.

He has campaigned heavily on the issue, warning supporters Thursday that migrants would soon be “overwhelming your schools, your hospitals, your communities.”

Obama said the deployment was serving to “get folks angry and ginned up,” adding: “There’s just constant fear-mongering to distract from the record.”

The nation’s first African American commander in chief took the stage with Andrew Gillum, who is locked in a tight race for governor of Florida against pro-Trump Republican Ron DeSantis, and Senator Bill Nelson, who is running for re-election against outgoing Governor Rick Scott.

“Let’s make history happen right here in Florida,” Obama told jubilant supporters at the end of a speech that was occasionally interrupted by pro-Republican protesters.

Obama urged more decisive action by Americans who have grown frustrated by the first 21 months of Trump’s presidency.

“If you don’t like what’s going on right now, don’t just complain,” Obama said.

“Don’t get anxious and freaked out, don’t throw up your hands in despair. Don’t boo. Don’t hashtag. Vote!”

In the home stretch of a campaign marked by a recent deadly anti-Semitic attack and the interception of parcel bombs sent to prominent Democrats including Obama, the former president called for defending “the values that bind us to our fellow citizens, no matter who we are.”

But he also drilled down on core Democratic issues for the 2018 campaign, like health care and preserving protections for people with pre-existing conditions.

Obama, architect of the Obamacare health reforms that he signed into law in 2010, took Republicans to task for “suddenly” saying they will protect pre-existing conditions coverage despite seeking to pass legislation to do away with such protections.

“Let’s call it what it is. It’s a lie. They’re lying to you,” Obama said.

Americans on Tuesday will elect lawmakers for all 435 seats in the House of Representatives, 35 seats in the 100-member Senate, 36 governors and dozens of state legislatures.