Afghanistan and Tajikistan opened a US-funded bridge over the Pyanj River on Sunday to increase trade but Tajikistan’s president expressed concern it should not become a new route for illegal drugs, Reuters reported.

The US government, with contributions from Norway, Japan and the European Union, has invested US$37 million in the 600-metre (1,800-feet) bridge linking the Tajik town of Lower Pyanj and Afghanistan’s Sherhan-Bandar.

US Commerce Secretary Carlos M. Gutierrez attended the opening ceremony for the span.

"It will become the widest connection between Afghanistan and the rest of the world," he said, adding the bridge will support the trade and investment flow to the region.

Afghanistan and Tajikistan have agreed to create free economic zones on both sides of the bridge and ease customs and visa regimes to promote trade.

In the first seven months of 2007, the two-way trade was a modest US$15.6 million or around 0.7 percent of Tajikistan’s overall foreign trade.

"This bridge will not only link brothers and sisters, but will also improve our trade and economic cooperation ... and contribute to improving lives of our people," Afghan President Hamid Karzai told the ceremony.

Tajik President Imomali Rakhmon appeared more concerned by a possible impact of the new transport route on drugs trade from Afghanistan — one of the main security threats for the regional states.

"It is necessary to prevent this bridge from being used for drug traffic," he said. "It should remain the bridge of friendship and cooperation."

Political instability and unending insurgency in Afghanistan, where US-led forces toppled Taleban rulers in 2001, has contributed to the growth of drug traffic from the country to Europe via Tajikistan and other ex-Soviet states.

The regional states struggle to stop the flow and have expressed fears that drug routes could be also used to spread Islamic insurgency across Central Asia.

Earlier this month, the Shanghai Cooperation Organisation, which comprises Russia, China, Tajikistan, Uzbekistan, Kazakhstan and Kyrgyzstan, committed itself to stronger involvement in economic and anti-drug aid to Afghanistan.