Chinese President Xi Jinping has called for more countries to join his sprawling infrastructure-building initiative as other leaders expressed support for a project Washington worries is increasing Beijing's strategic influence.

Key points: President Xi Jinping has pledged to open up his Belt and Road program to non-Chinese companies

President Xi Jinping has pledged to open up his Belt and Road program to non-Chinese companies He says $64 billion in new projects have been signed off at the forum

He says $64 billion in new projects have been signed off at the forum Concerns remain that the program is a "debt trap" for developing countries

Mr Xi spoke at a gathering of leaders to celebrate the multi-billion-dollar Belt and Road Initiative, his signature foreign project. The upbeat tone of the two-day forum, at which Russian President Vladimir Putin and other leaders praised the initiative, is a setback for the Trump administration, which is trying to discourage other countries from participating.

Mr Xi promised on Friday to promote high financial, environmental and other standards in response to complaints about debt and other problems.

That has the potential to heighten tensions with Washington by making the initiative more attractive to additional participants.

"We need to encourage the full participation of more countries and companies," the Chinese President said at the event.

Mr Xi tried to dispel complaints that the Belt and Road does little for developing countries that have borrowed from Beijing to build ports, railways and other facilities. Mr Xi said his government wants to "deliver benefits to all".

Additional agreements worth a total of $64 billion were signed during the forum, Mr Xi said. He gave no details of what those agreements covered or who signed them.

Concern that Belt and Road program is a 'debt trap'

A joint statement issued by leaders at the meeting expressed appreciation for the "important opportunities" created by Belt and Road and said it offers "potential for economic and social development".

Participants included the presidents of the Philippines, Kenya and Egypt, prime ministers of Italy, Greece and Pakistan and other officials from Indonesia, Germany and other countries.

Other governments welcomed the initiative launched in 2013 to increase trade by building ports, railways and other infrastructure across Asia, Africa and the Middle East. But some are struggling to repay Chinese loans, which has fuelled complaints about a possible "debt trap".

The Belt and Road Forum aims to portray the initiative as gaining increasing global support, analysts say. ( AP Photo: Andy Wong )

Critics also complain that too much of the work goes to Chinese state-owned companies and the initiative might lead to corruption and environmental damage.

The United States, Russia, Japan and India are concerned that Beijing is eroding their influence. US officials have warned other governments about potential debt problems and China's possible political motives.

More countries signing onto the Belt and Road is a "positive headline" for Mr Xi. ( Chinatopix/AP )

Forum follows slump in new projects

Mr Xi's government is trying to revive momentum for Belt and Road after the number of new projects slumped last year. That followed official announcements that Chinese lenders would examine borrowers more closely amid concerns by some governments about Beijing's rising influence.

On Friday, Mr Xi promised to embrace international financial, environmental and other standards. He pledged to work more closely with multinational entities and to open projects dominated by Chinese state-owned companies wider to private and foreign contractors.

Despite US opposition, the Chinese Government says the number of countries that have signed agreements to support the initiative has risen to 115 from 65.

Sri Lanka agreed to hand over a port to China to help pay down its debts. ( Wikimedia Commons )

Beijing scored a diplomatic coup in March when Italy, a member of the Group of Seven major economies, signed an agreement to support Belt and Road.

"We welcome the participation of multilateral and international financial institutions in Belt and Road investment and financing, and we encourage third market cooperation," Mr Xi said.

"With involvement of multiple stakeholders, we can surely deliver benefits to all."

Mr Xi's promises on debt, transparency and anti-corruption "will be well received by some BRI countries and outside observers," Kelsey Broderick of Eurasia Group said in a report. Others including the European Union "will wait to see actual implementation".

Chinese lenders have provided $440 billion in financing for Belt and Road projects, the country's central bank governor, Yi Gang, said on Thursday.

Beijing is ordering Chinese state-owned companies to pay more attention to local economic development, benefits for local residents and environmental protection, the chairman of the cabinet agency that oversees national-level government industries said, according to a transcript on the agency website.

Sorry, this video has expired What happens when developing countries can't repay their Chinese loans?

Mr Xi's government also has tried to defuse tensions with Belt and Road participants by renegotiating debts or offering other concessions.

Ethiopia announced on Wednesday that Beijing had forgiven interest payments owed by the north-east African nation through the end of 2018.

AP