US Republican vice presidential candidate James David Vance says the US will use military force abroad “only when necessary” if former US leader Donald Trump wins the presidential election.

“We will only send our children to war when necessary,” he said, speaking at the Republican national convention in Milwaukee, Wisconsin.

“President Trump has shown with the destruction of IS and many other actions: when we hit, we hit hard,” Vance asserted.

The Republican Party convention kicked off in Milwaukee on July 15. On the first day, delegates nominated Trump as the party's presidential nominee and Senator Vance as the vice presidential nominee. The US presidential election will be held on November 5. The current US President, 81-year-old Democrat Joe Biden, running for a second term, has already secured the support of a sufficient number of delegates from the Democratic Party, whose convention will be held in August.