Joe Biden went on the offensive in the third Democratic debate of the 2020 White House race (AFP)

The US can stop being a victim of terrorism emanating from Afghanistan if it insists that Pakistan provide it with bases to conduct operations against terrorists in the war-torn country, Democratic presidential front-runner Joe Biden has said.

Biden went on the offensive on Thursday in the third Democratic debate of the 2020 White House race.

The 76-year-old former vice president pushed hard against rival liberals Bernie Sanders and Elizabeth Warren in an almost three-hour showdown in Houston, Texas.

He was sharper and more aggressive than in either of the first two debates and clashed with rivals on the issue of health care in America.

"Here's the point, the point is that it's a counter-terrorism strategy. We can prevent the United States from being the victim of terror coming out of Afghanistan by providing air bases and insisting the Pakistanis provide bases for us to airlift from and move against what we know," he was quoted as saying by the New York Post.

The US, which has been fighting a longstanding war in Afghanistan, has about 14,000 troops in the country.

US President Donald Trump's US negotiator Zalmay Khalilzad had announced a peace deal "in principle" with the Taliban. He said as part of the proposed deal, the US would withdraw 5,400 troops from Afghanistan within 20 weeks.

However Khalilzad said final approval still rested with Trump.

Trump recently cancelled a "secret" summit with Taliban leaders and his Afghan counterpart after the insurgent group claimed responsibility for a deadly attack in Kabul that killed an American soldier and 11 others, dealing a body blow to protracted negotiations that were nearing a peace deal to end America's longest war.

Trump was to meet Afghan President Ashraf Ghani and senior Taliban leaders on Sunday last week at his Camp David retreat.

His move came after nine rounds of talks between the US and Taliban representatives, held in Doha, the capital of the Gulf state of Qatar.