A Chinese visa agency that handled South Korean business travelers was stripped of its business license, a move that could be seen as a retaliatory measure undertaken by Beijing after South Korea's decision to deploy an advanced United States missile defense system on its soil, a local source here said Wednesday.

The source said the closed agency handled Chinese letters of invitation for South Koreans, which is a key piece of paperwork needed to get multiple entry visas for business trips and cultural exchanges.

Such visas are valid for six months to a year and allow the holders to travel to China without limits during that time. This step is expected to have adverse effects on South Koreans wanting to visit the neighboring country.

China is South Korea's No. 1 trading partner, so there is usually a large flow of business-related traffic between the two countries.

Related to the latest developments, some observers said China may be trying to get back at South Korea for agreeing to station the Terminal High Altitude Area Defense battery by the end of next year.

China has vehemently protested the deployment plans, claiming that it would compromise its own strategic interests.

South Korea's foreign ministry confirmed China's decision to revoke the license of the visa agency, but said this does not mean China has stopped issuing long-term, multi-entry visas altogether.

"Although no more letters of invitation will be issued from that particular agency which had its business license canceled today, South Korean companies will still be able to get long-term visas normally if they secure letters of invitation (directly) from their partner firms in China," the ministry said, quoting the Chinese Embassy in Seoul. (Yonhap)