HARBIN -- Northeast China's Heilongjiang province is planning to increase investment in Russia by $1 billion by the year 2015, and $2 billion by 2020, local authorities said Sunday.

The province that borders Russia will also beef up its trade with the country, vowing to boost its trade volume to $26 billion by 2015, and $52 billion by 2020, sources with the provincial commercial department said.

Heilongjiang accounts for about a quarter of China's total trade with Russia. Trade between the province and Russia in 2012 rose 12.2 percent year-on-year to $21.3 billion, according to a statistics communique released by the provincial government earlier this month.

Chinese President Xi Jinping has just wrapped up a four-state tour that included Russia as his first stop.

During the visit, Xi and Russian counterpart Vladimir Putin vowed to make full use of various cooperation mechanisms, and invigorate collaboration on large joint projects of strategic significance.

The two leaders also pledged to improve the structure of bilateral trade and strive to advance toward the goal of bringing bilateral trade to $100 billion by 2015.

After Xi's visit, the Heilongjiang commercial department has held seminars to look into deepening economic and trade relations with Russia.

Department head Meng Xiangjun said Xi's visit to Russia would bring the economic and trade cooperation between the two countries to a new stage.

According to experts, Heilongjiang province should push forward its cooperation with Russia in fields including energy, agriculture, forestry, infrastructure and logistics.

In the meantime, they say, it should work out industrial cooperation plans to take the lead in broadening Sino-Russian cooperation.