IRKUTZSK, Russia - Chinese and Russian delegations to an international economic forum here Tuesday had an open and heated discussion about how to establish mutual trust and improve bilateral investment environment.

The dialogue, which was held under the framework of the seventh Baikal International Economic Forum that started Monday, was devoted to issues of Russian-Chinese cross-border and inter-regional economic cooperation.

However, the two sides started the talks with complaints on each other's problems that have made the investment environment not so friendly.

Citing a report by the World Bank, which ranked China as the world's No 22 and Russia behind the 100th in terms of ability of drawing foreign direct investment, the Chinese delegation pointed out the Russian investment market is not open nor attractive enough for Chinese capital.

"Since Chinese companies could make more money at home, why should they run the risk of investing in the Russian economy?" asked Wang Huajiang, an official of China's National Development and Reform Commission.

Wang, who is in charge of establishment and implementation of major Sino-Russian cross-border cooperation projects, assured his Russian colleagues that fast development of Chinese economy will never impose threat to nor endanger its neighbors.

"Some Russians should abandon the menace theory upon China's development. If not, our cooperation could not be further deepened," the Chinese official said.

Moreover, port construction along the Russia-China border has nearly been halted over the past five years, he said.

In its turn, the Russian delegation, headed by Russian Regional Development Minister Victor Basargin, complained many Chinese investors are only interested in big projects.

"They don't cast an eye at the small- or medium-size projects," said Geniatulin Ravil Faritovich, governor of the Zabaykalsky Krai federal region, adding some investors always intend to become major share-holders in joint enterprises.

After listening to and debating on the questions, both sides admitted there are still many obstructions caused by differences in culture and the two countries' characteristics. They pledged to continue improving the investment environment, including to further open the markets to each other, give stronger state policy support, speed up infrastructure building and boost government efficiency.

Zhang Guobao, former head of China's National Administration of Energy and a veteran energy expert, told Xinhua that he was glad to witness such an open and frank discussion, which was very rare to happen in front of reporters.

"You can see what the main obstacle for our two countries' economic cooperation is. It's not about money, but about the establishment of mutual trust and mechanism of coordination," he said.

Zhang, who has participated in the economic forum twice so far, believed this kind of debating would help clear up obstacles and promote mutual investment, because it showed China and Russia have both been aware of the limitations and begun to search for solutions.

"Things have started to change gradually. In 2005, China Development Bank launched a 6-billion-US-dollar loan to a Russian company, which was regarded a quite controversial and risky decision at that time because investors were not confident about the repay ability of Russian market," recalled Zhang.

Till now, the past six years has proved the success of this investment, Zhang said, adding it went on well and the Chinese bank has expanded its business in Russia.

The Chinese delegation, comprising of some 100 members, along with more than 1,500 other representatives from over 20 countries, took part in the three-day Baikal forum this year.