China and Serbia signed on Wednesday two roadbuilding deals worth a total of nearly four billion euros ($4.2 billion) as well as a contract on the purchase of five high-speed trains, the Serbian transport ministry said.

The contracts were signed in Beijing a day after the two countries signed a free trade agreement at a forum on China's landmark Belt and Road Initiative (BRI) as Beijing seeks to shore up alliances amid tensions with Western powers.

The roadbuilding contracts, totalling up to four billion euros, will enable Serbia to get nearly 300 kilometres (186 miles) of new roads and highways, a ministry statement said.

"It is a major contribution to the continuation of road infrastructure building," the statement quoted Transport Minister Goran Vesic as saying.

Also, "for 54 million euros, we received five trains, meaning that we will now have high-speed trains, Chinese trains, that will run on the Belgrade-Budapest railroad", he said.

Some of the trains will start operating in early 2025, linking the capital Belgrade with the northern town of Subotica.

"When our Hungarian friends finish their part of the railroad we will go to Budapest."

No details on the financing of the projects was provided in the statement and AFP has sought clarification from Serbian authorities.

Chinese investments in Belt and Road infrastructure projects are generally made via loans while the works are performed by Chinese companies, with some countries having encountered difficulties repaying their debts.

China has invested billions in Serbia and neighbouring Balkan countries in recent years, hoping to expand its economic footprint in central and eastern Europe.

In September, Belgrade said that Chinese state-owned company Zijin Mining will invest $3.8 billion into the mining complex in the eastern city of Bor.

Serbia, which aspires to join the European Union, has been quick to cash in on China's interest, with Belgrade seeking to court a range of investors amid the ongoing tug of war between the East and West over influence in the Balkans.

Last year, around a third of foreign investments in Serbia came from China, amounting to nearly 1.4 billion euros, according to Belgrade's figures.

In 2022, China was Serbia's second largest foreign trade partner -- after Germany -- with the volume of trade between the between the two countries totalling $6.15 billion.