MADRID, March 23 (Reuters) - Spanish Prime Minister Pedro Sanchez will visit China next week following a formal invitation by President Xi Jinping, as the Asian country seeks to position itself as a mediator in the ongoing war in Ukraine.

The invitation, first reported by newspaper El Pais on Wednesday, was later confirmed by Minister for the Presidency Felix Bolaños in an interview with radio station Cadena Ser.

"The trip will take place next week. The weight that Spain and Pedro Sanchez have in the world is unquestionable," Bolaños said, adding that "China has a key role to play in mediating the war".

Bolaños said the visit would also be important from a trade and economic perspective, as Sanchez plans to meet with the Asia Pacific Forum and Spanish businesses operating in China.

Xi has just concluded a three-day trip to Moscow, where he described China's position on the conflict as "impartial". Last month, Beijing put forward a 12-point peace plan and called for a comprehensive ceasefire.

Spain, a NATO member whose foreign policy is closely aligned with the United States, is a staunch ally of Ukraine and will assume the presidency of the Council of the European Union in July.

In a trip to Kyiv on the eve of the one-year anniversary of the Russian invasion, Sanchez expressed his "unconditional support" to Ukrainian President Volodymyr Zelenskiy and backed the latter's peace proposal, which includes demands to restore Ukraine's territory to the status quo before Russia's 2014 annexation of Crimea.

Sanchez is set to take part in the Boao Forum for Asia - similar to the World Economic Forum held in Davos - in China's Hainan province on March 30 before heading to Beijing the following day to meet with Xi.

The latest bilateral talks between the two leaders took place in November 2022 during the G-20 summit in Bali, Indonesia.