Afghanistan's new president Ashraf Ghani arrives in Beijing on Tuesday, kicking off a four-day visit to the resource-hungry Asian giant as NATO combat troops prepare to withdraw by the end of the year.

Ghani, once a US-based academic, was sworn in as Afghan president last month in the war-torn country's first democratic transfer of power.

He is accompanied by a high-level Afghan government delegation and is expected to meet Chinese President Xi Jinping and other leaders in Beijing, which is seeking greater investment opportunities in Afghanistan.

Ghani will also sign a raft of bilateral agreements and on Friday attend the Istanbul Process, a key conference on his country, which is being hosted by Beijing this year.

China shares only a 76 kilometre (47 mile) border with Afghanistan's remote far northeast, but has a keen interest in its neighbour's mineral resources.

It has already secured major oil and copper mining concessions in Afghanistan, which is believed to have more than $1 trillion worth of minerals.

Ghani's choice of China for his first overseas trip since taking office suggests that the Afghan leader is eyeing closer economic ties with Beijing, analysts say.

"Seeking other sources of support is essential to Afghanistan's stability and development," China Institute of Contemporary International Relations research fellow Fu Xiaoqiang told the state-run Global Times newspaper.

"China, as the most capable nation in the neighbourhood, has to be its first option," Fu added.

But there are questions over stability in Afghanistan, particularly after US troops pull out by the end of this year.

There are now about 40,000 foreign troops in Afghanistan, down from their 2011 peak of around 140,000.

All NATO combat troops will depart the country by December, leaving Afghan troops and police to battle Taliban insurgents on their own.

A residual force of around 12,000 soldiers including 9,800 Americans and 500 Britons will remain under a security pact signed by Ghani. They will focus on training local forces and counter-terrorism.

China's role in the Middle East has come under criticism from some parties including US President Barack Obama, who in an August interview with the New York Times called Beijing a "free rider" for not doing more to quell violence in the region.

China's state-run media struck back with a litany of editorials blasting Obama's remark.

"The US accusation, which comes out of nowhere, is nothing but an attempt for Washington to find a scapegoat for its failed policy in Iraq," the official Xinhua news agency wrote last month.