KABUL (Reuters) - Afghan forces are suffering rising levels of battlefield casualties this year after unprecedented numbers of police and soldiers were killed and wounded in 2015, the top U.S. commander in Afghanistan said.

An Afghan National Army (ANA) soldier stands guard after the inauguration of the reconstruction project to restore the ruins of historic Darul Aman palace, in Kabul, Afghanistan May 30, 2016. REUTERS/Omar Sobhani

U.S. Army General John Nicholson, in some of his first remarks since the United States last week scaled back its withdrawal plans, told a small group of reporters that the rising casualties were largely the result of Taliban attacks on fixed Afghan positions.

“This year, we’re seeing more tactical success (by the Afghans) on the battlefield but more casualties as well,” Nicholson said late on Saturday when asked about how Afghan forces were faring this year compared with 2015. He did not disclose figures.

A spokesman told Reuters on Sunday that Nicholson was referring to an increase so far in 2016 compared with the same period in 2015, and noted how fighting was more intense due to the milder winter this year.

“It’s when they’re in a defensive posture, such as in checkpoints being overrun, is where the majority of the casualties are occurring,” Nicholson said.

More than 5,000 forces in Afghanistan were killed in action and over 14,000 were wounded in 2015, when the Taliban staged a series of attacks that upended U.S. assumptions about the ability of Afghan forces to secure the country after more than 14 1/2 years of war.

On July 6, U.S. President Barack Obama scrapped plans to slash the number of U.S. forces to 5,500 troops from 9,800 before he leaves office, citing precarious security in Afghanistan.

Obama now plans to leave around 8,400 U.S. troops.

U.S. allies are also renewing their commitments, and NATO agreed on Saturday to help fund Afghan forces to the tune of around $1 billion annually over the next three years.

Nicholson praised Afghan forces for being able to recruit new fighters and carry on, despite the casualty rates. He said their losses could be addressed, including by replicating successful efforts to rapidly reset and retrain Afghan forces in southern Helmand province after their dismal performance last year.

Major General Moeen Faqir, the new commander of the 215th Corps in Helmand, told reporters his casualties were sharply down this year from 2015.

Nicholson also suggested the Afghan Taliban were struggling after the U.S. killed their leader, Mullah Mohammad Akhtar Mansour, in a May drone strike across the border in Pakistan.

Mansour had tight control of Taliban finances, Nicholson said.

“So what we’re seeing are some indications that some of the finances of the organization have been disrupted,” he said.

Nicholson suggested Mansour’s successor, Mullah Haibatullah Akhundzada, had also alienated some fighters in the past.

“So he’s not a unifying figure within that organization,” he said.