Afghan President Ashraf Ghani and his rival Abdullah Abdullah signed a power-sharing deal on Sunday, ending a bitter months-long feud that plunged the country into political crisis.

The breakthrough, which sees Abdullah heading peace talks with the Taliban, comes as Afghanistan battles a rapid spread of the deadly coronavirus and surging militant violence that saw dozens killed in brutal attacks last week.

The United States and NATO welcomed the agreement, with both calling for a renewed peace push in the war-wracked country. "Doctor Abdullah will lead the National Reconciliation High Commission and members of his team will be included in the cabinet," Ghani spokesman Sediq Sediqqi said on Twitter.

Abdullah's spokesman, Fraidoon Khawzoon, told AFP the agreement ensures that Abdullah's group will get 50 percent of cabinet positions and other provincial governors' posts. Ghani hailed a "historic day" for Afghanistan, noting that the agreement was reached without any international mediation. "We will share the burden and our shoulders, God willing, will be lighter," he said, addressing Abdullah at the signing ceremony broadcast on a state-run television channel.

"In the days ahead, we hope that with unity and cooperation, we would be able to first pave the ground for a ceasefire and then lasting peace." Abdullah said the deal commits to forming a "more inclusive, accountable and competent administration". "It's meant to ensure a path to peace, improve governance, protect rights, respect laws and values," he said on Twitter after signing the deal.

The agreement says that Ghani will make Abdul Rashid Dostum, his former vice president turned ally of Abdullah, a marshal of the armed forces.

Dostum, a notorious former warlord, is accused of ordering the torture and rape of a political rival in 2016. The United States, which wants to salvage the peace process and end its involvement in what has become its longest war, expressed hope that talks could now move forward. Secretary of State Mike Pompeo told Ghani and Abdullah "that the priority for the United States remains a political settlement to end the conflict," his spokeswoman said in a statement.

NATO, which maintains a training mission in Afghanistan, issued a similar message.

"We call on the Taliban to live up to their commitments, reduce violence now, take part in intra-Afghan negotiations, and make real compromise for lasting peace," NATO chief Jens Stoltenberg said in a statement. Pictures released by the presidential palace showed Abdullah and Ghani sitting side-by-side for the signing ceremony, while leading Afghan figures including former president Hamid Karzai looked on.

Abdullah had previously served as Afghanistan's "chief executive" under an earlier power-sharing arrangement, but lost that post after he was defeated in a presidential election that incumbent Ghani - a former World Bank economist - won in September amid claims of fraud.

Abdullah, an ophthalmologist, declared himself president and held his own swearing-in ceremony on March 9, the day Ghani was re-installed as president. Experts feel Sunday's deal could help pull Afghanistan out of political crisis.

In February, the Taliban signed a landmark accord with Washington to clear the way for the withdrawal of foreign forces from Afghanistan, but intra-Afghan talks have stalled.

"It is now expected that these leaders resolve the problems that Afghanistan faces such as the coronavirus and peace talks with the Taliban," Kabul-based political analyst Sayed Nasir Musawi told AFP.

He said "immense pressure" from the United States pushed the rivals to agree to the deal.

Abdullah and Ghani also contested the 2014 presidential election, with both claiming victory.

To avert a full-blown conflict, then-US secretary of state John Kerry brokered a deal between the two that left Abdullah as the country's chief executive.

But after a similar impasse in March, an exasperated Pompeo lashed out at their failure to reach an agreement, and announced a $1 billion cut in aid to Afghanistan. With the impoverished country's GDP just $20 billion, the cut was a devastating blow to its donor-dependent economy. Several residents in the capital Kabul expressed scepticism at the deal. "If they really want to work for the country ... they have to bring genuine peace to the country - that is the only thing the majority of Afghans want," said Rashed Hashemi, an employee at a private company.

US President Donald Trump has made leaving Afghanistan a priority. The February deal stipulates that the US and its foreign allies will withdraw all forces by early 2021. In return, the Taliban agreed not to attack foreign troops. But fighting between the Taliban and Afghan forces rages on, with both sides threatening to go on the offensive after two attacks last week that left dozens dead, including mothers and infants slain at a hospital in Kabul.