MADRID—Chinese Vice Premier Li Keqiang Wednesday reiterated Beijing's pledge to support Spain in a meeting with the country's prime minister, José Luis Rodríguez Zapatero, as the two countries began signing $7.3 billion in deals.

Mr. Li, widely expected to become China's next premier within the next two years, told Mr. Zapatero that China wanted a united, strong and stable Europe, with Spain an important player in multilateral international relations.

"China...