A train carrying up to 28 million masks from China has arrived at its final destination in Spain after a month of travelling, Spain`s Health Ministry said Thursday.

The freight train with 35 cars also brought up to 425,000 units of protective body covering for medical workers. The volume of the cargo is equivalent to four aeroplanes, the ministry said.

The train left the Chinese city of Yiwu on June 3 and traversed the longest rail path in the world of 13,025 kilometres. It crossed eight nations on its path: China, Kazakhstan, Russia, Belarus, Poland, Germany, France before finally reaching the Spanish capital of Madrid.

"The Ministry of Health is optimizing the cost of importing this type of product, since rail transport is fifteen times cheaper than by air. This type of transport is intended for those materials that the national health system already has and therefore its need is not urgent," the health ministry`s statement read.

In a telephone conversation in March between Chinese leader Xi Jinping and Spanish Prime Minister Pedro Sanchez, Xi assured Sanchez of China`s continued backing and reassure him that "the sun will come out after the storm," according to the Chinese Foreign Ministry.