Afghanistan's Helmand province is on the verge of falling to the Taliban with 90 soldiers killed in two days of fierce clashes, its deputy governor said.

Mohammad Jan Rasoolyar pleaded with President Ashraf Ghani through Facebook on Sunday for urgent intervention to save the province that British and US forces struggled for years to defend.

"I know that bringing up this issue on social media will make you very angry," Rasoolyar wrote in his Facebook post addressed to Ghani. "But I cannot be silent any more ... as Helmand stands on the brink. Ninety men have been killed in Gereshk and Sangin districts in the last two days."

No immediate reaction on Rasoolyar's post was given from Ghani's office. 

The defence ministry in Kabul strongly denied that Helmand would fall and rejected claims of 90 deaths.

But local officials backed Rasoolyar's assertions, saying the Taliban were making steady gains in districts such as Sangin.

 Securing Afghanistan after the US withdrawal

Fall of Kunduz

Rasoolyar's post bore similarities to the security situation that led to the brief fall of the northern city of Kunduz in September - the biggest Taliban victory in 14 years of war.

The fall of Helmand would deal another stinging blow to the country's NATO-backed forces as they struggle to rein in the unrest.

This month marks a year since the US-led NATO mission in Afghanistan transitioned into an Afghan-led operation, with allied nations assisting in training local forces.

US President Barack Obama in October announced that thousands of US troops would remain in Afghanistan past 2016, back-pedalling on previous plans to shrink the force and acknowledging that Afghan forces are not ready to stand alone.

Rasoolyar is the second official to take to Facebook to air his frustration.

Afghanistan's spy agency chief resigned earlier this month after a scathing Facebook post against Ghani's diplomatic outreach to Pakistan - the Taliban's historic backers - aimed at restarting peace talks with the armed group.

Rahmatullah Nabil's resignation raised uncomfortable questions about a brewing leadership crisis in Afghanistan as the Taliban unrest gains new momentum.

Source: AFP