ABUJA, May 8 -- China and Nigeria have agreed to deepen their pragmatic cooperation in key fields so as to strengthen their strategic partnership, according to a joint statement released here Thursday.

The statement was issued during Chinese Premier Li Keqiang's official visit to Nigeria, where he signed a number of cooperation deals with the West African country.

According to the statement, the two sides would encourage their companies to expand cooperation in infrastructure, in particular railways, power plants and airports.

Both countries reaffirmed their commitment to promoting bilateral trade and addressing the trade imbalance.

In addition, they agreed the economic cooperation zones established by Chinese enterprises in Nigeria had achieved progress, it said.

The Chinese side would continue to encourage Chinese enterprises to invest in various fields of the Nigerian economy, while the Nigerian side would fulfil its commitment to provide preferential treatment and to offer supporting facilities to the economic cooperation zones, it said.

On financial cooperation, the two sides reaffirmed support for financial institutions in the two countries to cooperate in re-lending to small-and-medium-sized enterprises in Nigeria, it said.

Both sides agreed the central banks of the two countries would promote local currency settlement to facilitate bilateral trade and investment, it said.

On agriculture, the two sides agreed to expand cooperation so as to help Nigeria reduce poverty and enhance food security.

On space and aviation cooperation, both sides commended the positive role of their communication satellite project in promoting the development of Nigeria, and expressed willingness to enhance cooperation in satellite technology.

The two sides considered the signing of a bilateral air services agreement as an opportunity to further deepen cooperation in the field of aviation, the statement said.

Nigeria is the second leg of Li's four-nation Africa tour, which will also take him to Angola and Kenya. Before Nigeria, Li paid a visit to Ethiopia, where he also visited the African Union headquarters and delivered a speech there on China's Africa policy.