The main body of the Chinese part of the first cross-river railway bridge connecting the country with Russia was completed on Saturday, the construction contractor said.

Chinese workers put in place the last steel beam to connect bridge pillars on Saturday morning.

The bridge across the Heilongjiang River, known as the Amur River in Russia, will connect the city of Tongjiang, in northeastern China's Heilongjiang province, with Nizhneleninskoye in Russia.

The main bridge spans 2,215 meters, with 1,886 meters of that standing in China. Construction of the bridge, which has a designed annual throughput capacity of 21 million metric tons, began in February 2014.

Liu Weiquan, head of China's bridge construction headquarters, said the Chinese side only has a small number of railway tracks to lay before full completion and the Russian side is also speeding up construction.

The bridge is expected to be a major transportation corridor between China and Russia and help Heilongjiang province take advantage of the Belt and Road Initiative to boost the local economy and trade.

"After the railway bridge is put into operation, we can import through the year, and this is also expected to reduce transportation costs by 100 yuan ($15) per cubic meter of timber," said Xu Zhaojun, a timber importer in Tongjiang.

Song Kui, president of the Contemporary China-Russia Regional Economy Research Institute in Heilongjiang, said the new route will give economic cooperation between the two countries further impetus.

In the first half of this year, Heilongjiang saw trade with Russia increase by 48.2 percent year-on-year to 53.4 billion yuan.

China is the largest trading partner and source of foreign investment for the Russian Far East.