Nigeria, Sept. 10 -- US President Donald Trump has promised to pay every adult citizen in the US $5,000 if Republicans retain the House and Senate in the midterm elections.

He said this at the party's convention on Wednesday in the middle of a US presidential term and ahead of the midterms, expected to be held on 3 November.

The proposal will cost over $1 trillion and has raised ethical concerns. Mr Trump's proposal aims to induce US citizens to vote for Republicans, with a direct financial reward conditioned on his party winning.

His statement also made Republicans' concerned about their prospects in the November elections obvious.

"If the Republicans win, you win with us, and you get $5,000," he told the crowd of supporters present ...