By Ian Bruce
BBC News, Caracas
Venezuela and Spain have signed a number of trade agreements, including the controversial sale of Spanish military equipment.
Mr Zapatero said the plan would help Venezuelan border security
Opposition parties in both countries have criticised the deal reached in Venezuela's capital, Caracas.
But Venezuelan President Hugo Chavez and Spanish Prime Minister Jose Luis Rodriguez Zapatero said the equipment would be used for peaceful purposes.
It includes Spain's naval patrol vessels and military transport planes.
'Instruments of peace'
The agreements were signed at the end of Mr Zapatero's two-day visit to Venezuela.
Several of the deals involve Spain's and Venezuela's respective oil companies, PDVSA and Repsol.
But the most controversial is the sale of Spanish coastal patrol vessels and C-295 transport planes to the Venezuelan military.
Opposition parties in the two countries have criticised the arms deal, echoing earlier concerns by the US of Venezuela's plans to buy helicopters and guns from Russia.
But President Chavez said these were not weapons of war but instruments of peace.
The boats will be used, he said, to step up Venezuela's coastal patrols against the drugs trade.
While the transport planes would be used mainly for humanitarian missions inside and outside the country.
Mr Zapatero said he believed the criticisms levelled by the Spanish opposition were based on lack of information rather than any other intention.