"China would still be the single-largest contributor to contribute over one-quarter of global growth this year," Barnett said in an exclusive interview with China Daily, adding that the over-a-quarter contribution is yet to add in the positive spillover of China's growth on other economies.

According to the IMF's latest forecasts, China's economy is projected to grow 4.6 percent this year, compared with 5.2 percent in 2023. The world economy is expected to grow 3.1 percent in 2024, unchanged from last year.

In 2023, US' nominal GDP growth outpaced China, sparking discussions of a widening US-China GDP gap.

Barnett said he does not take it as a sign that China is lagging behind the US further when it comes to economic strength.

"In terms of real growth, China grew last year at double the rate of the US economy."

China has, however, seen a gradual economic slowdown since even before the pandemic, Barnett said, underlining the necessity for China to pursue reforms to generate growth and further boost people's living standards.

Priorities of the reforms should include giving the market a more decisive role in the economy, ensuring a level playing field between all types of firms and improving the business environment, Barnett said.