China's finance minister defended Beijing's Belt and Road initiative on Thursday, pledging to create a sustainable financing system to pay for infrastructure projects.

Critics say the project — which aims to connect Asia to Europe and Africa through huge maritime, road and rail projects — could mire poorer countries in debt.

Finance Minister Liu Kun was speaking at the start of the second Belt and Road Forum in Beijing.

What's happening at the summit?

• The three-day forum brings together leaders or representatives of dozens of countries seeking to benefit from the projects.
• Russian President Vladimir Putin and Italian Prime Minister Giuseppe Conte are among the headline guests.
• EU powers Germany and France are sending ministers, but the US has dispatched only a low-level delegation.
• The leaders of Asian and African countries are expected to urge Beijing to reduce financing costs for Belt and Road projects.

What's being said?

Finance Minister Liu told those gathered that Beijing would pursue "stable and sustainable financing." Chinese regulators would work with banks and multinational institutions to "build a high-quality, high-standard, sustainable financing system," he said.

China's central bank governor Yi Gang said China would follow market principles and rely on commercial funds for the financing of Belt and Road projects.

"We should strengthen debt and risk management. We should objectively and fully understand debt problems of developing countries," Yi said.

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International Monetary Fund chief Christine Lagarde said the announcement by Foreign Minister Liu, and Beijing's increased focus on the long-term success of Belt and Road were "very welcome steps in the right direction."

What is the Belt and Road project?

The Belt and Road initiative is the signature foreign policy project of President Xi Jinping. It's a strategy that involves infrastructure development and investment in 152 countries globally.

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The aim is to reestablish traditional land-based connections (the "belt" part of the strategy) from China to other parts of Asia, Europe and beyond.

China also seeks to build strong sea connections — dubbed the 21st Century Maritime Silk Road — in the South China Sea, South Pacific and wider Indian Ocean. A northern Ice Silk Road is also envisioned.

Since the initiative was launched in 2013, China has invested some $90 billion in projects, with banks supplying some $200 billion to $300 billion.

Earlier this month, China sought to reassure the European Union that it would respect the bloc's trading rules while seeking a greater economic foothold in eastern Europe.