President Barack Obama says accepting immigrants from foreign shores is in America’s “DNA”, as the nation continues to roil over the arrival of thousands of undocumented minors.

At a Fourth of July event marking the 238th anniversary of American independence, Obama praised the newly minted citizens – some two dozen active duty military, their spouses, veterans and reservists – who “remind us that America is and always has been a nation of immigrants”.

The president’s remarks at the White House came with the country embroiled in a tense debate over how to stem an influx of undocumented immigrants from Mexico and Central America, among them thousands of minors, who have flooded across the border into the United States in recent months.

“Throughout our history, immigrants have come to our shores in wave after wave, from every corner of the globe. Every one of us – unless we’re Native American – has an ancestor who was born somewhere else,” Obama said.

“That’s what makes America special. That’s what makes us strong. The basic idea of welcoming immigrants to our shores is central to our way of life, it is in our DNA,” the president said.

The immigration issue has gained new urgency after some 52,000 unaccompanied minors crossed illegally into the US via America’s southern border since October.

Earlier this week, the tense debate took a contentious turn when residents of the California town of Murrieta refused to allow three busloads of 140 undocumented migrants from Texas relocate there.

With placards reading “Stop Illegal Immigration” and “Send Them Home”, protesters blocked the road, forcing the busloads of migrants to head instead to San Ysidro, near San Diego.