Donald Trump returned to the Republican National Convention Tuesday as his former opponents for the US presidency lined up to shower him with praise.

While Trump made no formal remarks, his appearance was more laid back than his dramatic post-assassination attempt entrance the day before.

Former rivals turned supporters

One-time UN ambassador Nikki Haley told the crowd in Wisconsin that a "unified Republican Party is essential for saving" the nation.

"I'll start by making one thing perfectly clear. Donald Trump has my strong endorsement," Haley told the crowd at the Republican National Convention in Milwaukee, Wisconsin on Tuesday.

Florida Governor Ron DeSantis said “let’s send Joe Biden back to his basement, and let’s send Donald Trump back to the White House," to loud applause.

Businessman Vivek Ramaswamy, who had also vied for the Republican nomination, meanwhile said: "Donald Trump is the president who will actually unite this country, not through empty words, but through action."

VP pick Vance to address delegates

Trump, still swearing a white bandage over his ear, has been feted as a hero for surviving Saturday's attack at a campaign rally. 

Wednesday will see running mate JD Vance address the 2,400 Republican delegates in attendance.

A one-time harsh critic of Trump, Senator Vance has become an unwavering supporter of the former president and a rising star in the Republican party.

Europe prepares for possible Trump presidency

With the Republicans leading in the polls, Europe has gone into planning mode as to how to deal with a second Trump presidency.

Conservative German lawmaker Jens Spahn told DW that "we should not make the same mistake again. Last time he became president no one really had a network with his team. No one really knew what [was] going on."

He conceded that there was even some common ground with Trump, such as countering the rising influence of China on the world stage.

 es/rmt (AP, AFP)