The China-Mongolia-Russia Economic and Trade Cooperation Fair opened on Wednesday with the inauguration of a center to process a cost-saving customs document in Erenhot, a city on the China-Mongolia border.

The center will handle ATA Carnets, an international customs document which allows duty-free temporary export and import of goods for up to a year.

Its establishment will help boost border trade, economic development and cultural exchanges, said Lu Ming, deputy head of the law department of the China Council for the Promotion of International Trade.

"With the service center, we will never have to make customs declaration for our costumes and stage properties when going abroad for performances," said Qiqige, a student with the art school of Inner Mongolia University who performed in Mongolia in July.

Erenhot, in the north of China's Inner Mongolia Autonomous Region, sits on the China-Mongolia-Russia railway and is the largest of a dozen ports along the 4,710-km China-Mongolia border, where the trade volume accounts for 70 percent of that between the two countries.

In June, the State Council, China's Cabinet, approved the city to pilot preferential policies in finance, taxation, investment and industries to deepen cooperation between China and Mongolia.

Chinese President Xi Jinping will pay a state visit to Mongolia from Thursday, his first visit to the country since taking office in March 2013 and also the first by a Chinese president in 11 years.

This year marks the 65th anniversary of the establishment of diplomatic relations between China and Mongolia and the 20th anniversary of amendment of the Treaty on Friendly Relations and Cooperation between the countries.

Trade between the two countries is booming, a dynamic which analysts say is key to rapid border development.

Last year, the bilateral trade volume between China and Mongolia reached nearly 6 billion U.S. dollars, 15 times the volume of a decade ago. Some 13 million tonnes of freight were exported or imported through Erenhot, up 12.5 percent year on year.

The China-Mongolia-Russia Economic and Trade Cooperation Fair, inaugurated in 2009, is one of the most important trade events for the China-Mongolia border region.

More than 400 exhibitors from China, Mongolia, Russia, the United States, Myanmar, Thailand, Vietnam and the Republic of Korea are attending the annual fair, which lasts until Friday.

It features exhibits ranging from clothes and accessories to heavy machinery and tourism services.

Related forums will also see attendees discuss regional cooperation including the Silk Road Economic Belt, the proposed network of trade infrastructure which covers the three countries.