Updated

U.N. experts say fighters loyal to al-Qaida have taken on a more active supporting role for the Taliban during the current offensive in Afghanistan while the position of the Islamic State extremist group in the country "has distinctly weakened."

In a report to the Security Council circulated Friday, the experts said the Afghan government and several other countries estimate that there are about 45,000 opposition fighters in Afghanistan and between 20 and 25 percent are foreigners.

It said these "bad actors ... mutually reinforced each other and presented a significant and rising terrorist challenge."

The experts said several governments highlighted that relations between the Taliban and al-Qaida strengthened during the time Akhtar Mansour led the Taliban and the improved relations have continued under his successor, Haibatullah Akhundzada.