Trump and Biden trade barbs on rival US-Mexico border visits

EAGLE PASS - Joe Biden and Donald Trump traded blame for America's immigration crisis as they made duelling visits to the US-Mexican border Thursday, putting the hot-button issue at the heart of their race for the White House in November.

In near-simultaneous speeches in Texas, Republican former president Trump called the record numbers of border crossings a "Joe Biden invasion" -- while the Democratic incumbent urged his rival to stop "playing politics" with proposed migration reforms.

The split-screen moment highlighted what could be a make-or-break issue in the presidential election less than eight months away, with polls showing most voters blame Biden for the unprecedented number of illegal entries. 

Hoping his long history of anti-immigration rhetoric can deliver an extraordinary White House comeback, 77-year-old Trump painted a dark picture of Americans "kidnapped", "raped" and "savagely murdered" by migrants.

"Joe Biden is responsible for this invasion," Trump raged during his speech in Eagle Pass, Texas, speaking alongside the state's hardline Republican Governor Greg Abbott.

Meanwhile Biden -- making just his second border trip since taking office in 2021 -- met border patrol agents and other law enforcement officials in Brownsville, Texas, about 480 kilometres to the east of Trump.

Migration is 81-year-old Biden's biggest political weak spot apart from his age, with Republicans blaming Biden's policies favouring the right to asylum for the flow of migrants.

But Biden is trying to turn the issue back on Trump by accusing him of sabotaging efforts to pass a bipartisan immigration bill that would give border forces more staff and money.

"Here's what I would say to Mr Trump," Biden said. "Instead of playing politics with this issue, instead of telling members of Congress to block this legislation -- join me."