Biden and Trump make competing trips to the US-Mexico border

President Joe Biden and Donald Trump have made competing trips to the US border in Texas, each trying to emphasize that they can deal with illegal immigration.

The issue is one of the most polarizing in American politics and will be central to this year's presidential election.

The November matchup will be another showdown between the two.

Mr Biden accused his Republican rival – who spoke of the “extremely dangerous” situation at the border – of blocking his efforts to crack down on the crossings.

Republicans in the House of Representatives have blocked bipartisan border reform, which Democrats say is a masterminded effort by Trump to deny them victory before the election.

In Texas, Mr Trump said he would “take care” of the illegal immigration issue if re-elected. He had previously promised mass deportations if he returned to power.

More than 6.3 million immigrants have been detained in the US illegally during Mr Biden's tenure – more than under any previous president, making the issue a serious focus.

However, experts say the reasons for the spike are complex — some factors pre-date his administration and sit outside U.S. control.

In his speech, Mr Trump said “thousands” of migrants from the Middle East and Africa cross illegally from Mexico. In fact, most of those caught are from Latin America.

While there is no national data that provides evidence of immigrant-driven crime waves in U.S. cities, he also attacked what he recently called “Biden's immigrant crime.”

Supporters and opponents gathered during Mr Trump's visit to the Democratic-run city of Eagle Pass, where Republicans are making political inroads by attacking Mr Biden's border runs.

Enriqueta Diaz, 81, told the BBC he supported Mr Trump's proposals to further militarize the border. “You have to follow the law,” she said, adding that her own mother, a Mexican, went through the citizenship process herself.

Mr Trump met with the state's governor, Republican Greg Abbott, who has battled the federal government by using his own powers to try to stop illegal crossings – as well as herds of migrants to northern cities.

Meanwhile, Mr Biden – who joked he didn't realize his “good friend” Mr Trump was due to arrive in Texas on the same day – went to meet border officials in Brownsville.

Mr Trump spoke later, stressing the urgency of action and the need for more resources to police the border. He said the bipartisan border reform bill was “derailed by standard partisan politics.”

He directly appealed to his rival to “join me” on this issue.

The president traveled to Texas with Interior Secretary Alejandro Mayorkas, the target of Republican ire over illegal immigration.

Earlier this month, Mr Mayorkas became the first US cabinet member to be sacked amid accusations from his political opponents that he had failed to do enough to curb illegal immigration.

Mr Biden has backed his colleague, who is unlikely to be convicted because the US Senate is narrowly controlled by members of his party.

Mr Trump has focused his political career on the issue of illegal immigration and embarked on building a border wall with Mexico during his 2016-20 presidency.

He is opposed only by Nikki Haley in her quest to win the Republican nomination to run for the White House again. For the Democrats, Mr Biden is largely unopposed in his own presidential bid.

The importance of the border issue is highlighted by the polls. More than two-thirds of people in a January poll by the BBC's US partner CBS said they disapproved of Mr Biden's handling of it.

In another Texan border town, Laredo, the manager of a community center described to the BBC how border agents were sending buses because of the “overwhelm” of migrants and asylum centers.

Beyond Texas, the influx of illegal immigrants has strained processing facilities and social services in major US cities – straining Mr Biden's relations with some Democratic government officials.

Migrants who recently arrived in Chicago – sent there from Texas under Mr Abbott's initiative – described their struggles to find accommodation and work to the BBC.

Karen Diaz, who entered the United States last month with her three children from Venezuela, said she prefers steady work to manual labor.

Dilcia Guillen-Oliva, who arrived from Honduras five days ago, said she was sleeping in a church and on public buses.

SB4, as it's known, wants to give authorities broad powers to arrest anyone suspected of crossing illegally from Mexico.

But in his ruling, Judge Biden sided with the administration, which argued that the proposed legislation would interfere with the federal government's powers. Mr Abbott vowed to appeal.