Trump credits new border wall with stopping migrants, and coronavirus

President Donald Trump has visited the US-Mexico border to celebrate the construction of more than 200 miles of wall, hoping it will remind voters of progress he has made towards one his 2016 campaign promises.

The president credited the wall with stopping not just illegal immigration, but also coronavirus, saying: "It stopped Covid, it stopped everything."

But his visit played out as top public health officials in Washington were testifying about the ongoing threat posed by coronavirus and singling out Arizona as one of the states now experiencing a surge in cases.

President Trump was looking to regain campaign momentum after his weekend rally in Tulsa, Oklahoma, which was supposed to be a sign of the nation's reopening and a show of political force but instead generated thousands of empty seats and swirling questions about the president's campaign leadership and his case for another four years in office.

The low turnout sharpened the focus on President Trump's visit to Arizona, which doubles as both a 2020 battleground state and a surging coronavirus hot spot.

By visiting the border, the president sought to change the subject to an issue he believes will help electrify his base in November.

"Our border has never been more secure," President Trump declared as he met with Republican Governor Doug Ducey and federal Border Patrol officials.

Throughout the trip, the Covid-19 pandemic is shadowing President Trump. The Democratic mayor of Phoenix made it clear she does not believe the speech can be safely held in her city — and urged the president to wear a face mask.

President Trump has refused to wear a mask in public, instead turning it into a red-vs-blue cultural issue. Polling suggests Republicans are far less likely to wear face coverings than Democrats despite health experts' warnings that it dramatically reduces the risk of transmitting the virus.

Since late May, Arizona has emerged as one of the nation's most active hotspots for the spread of Covid-19.

Arizona is seeing disturbing trends in several benchmarks, including the percentage of tests that prove positive for the virus, which is the highest in the nation.

The state reported a new daily record of nearly 3,600 additional coronavirus cases on Tuesday as Arizona continued to set records for the number of people hospitalised, in intensive care and on ventilators for Covid-19.

Arizona's total caseload in the pandemic stands at at least 58,179, with 42 more deaths reported on Tuesday, raising the death toll to 1,384.