International Monetary Fund chief Christine Lagarde says China's economic slowdown is legitimate and Beijing can contribute to global prosperity.

Lagarde welcomed Beijing's efforts to boost investment outside China, referring to the new Beijing-led Asian Infrastructure Investment Bank.

She was speaking Sunday at the opening of China Development Forum in Beijing.

China established the regional lending institution last year and put up most of its initial $50 billion in capital with the goal to finance construction of roads and other infrastructure.

At the forum, Chinese Vice Premier Zhang Gaoli said environmental protection and sustainably development will be Beijing's priorities.

The forum is an annual gathering of academics, entrepreneurs and representatives of multilateral organizations.