US presidential hopeful Joe Biden has promised to end “forever wars”, including pulling most troops out of Afghanistan and ending support for the Saudi intervention in Yemen.

The former vice-president to Barack Obama is bidding to be the Democratic Party’s nominee to run against Donald Trump in next year’s election.

Speaking in New York and quoted in a report by Sky News, Biden criticized Trump for “embracing dictators who appeal to his vanity” and emboldening the rise of nationalism and xenophobia.

He also accused the president of damaging America’s reputation and ability to lead on the world stage.

The 76-year-old pledged to “end the forever wars in Afghanistan and the Middle East” - but said military force would always be an option, Sky News reports.

However, he said any such action must be a “last resort” with an “achievable mission”.

Biden said most US combat troops would leave Afghanistan, with America “narrowly focusing our mission” in the region.

Ahead of Biden’s speech, the Republican National Committee criticized his judgment on foreign policy, saying that he had advised Obama not to carry out the raid that killed Osama bin Laden and served as “salesman” for the “disastrous” Iran nuclear deal.

This comes as a US Army Gen. Mark Milley told the United States lawmakers at a confirmation hearing Thursday that it would be a “strategic mistake” to prematurely pull American troops out of Afghanistan and that the international order is facing its greatest challenges since the fall of the Soviet Union.

Gen. Milley said the US is “living in a period of great-power competition with a very complex and dynamic security environment. [International order is] currently under the most stress since the Cold War.”