The move came after pressure on Sanchez's left-wing coalition government to take a more proactive approach to the war raging on Europe's eastern flank.

"Spain will give the Ukrainian resistance offensive military hardware," said Sanchez, without giving specific details on what that would entail.

He previously said Spain would only supply offensive capabilities through the EU's European Peace Facility (EPF), a 450-million-euro ($500 million) funding mechanism activated on Sunday to provide military aid to Ukraine.

"We are going to transfer offensive material through this European peace mechanism fund... which we Europeans will be able to use to provide offensive material to Ukraine," he said in an interview late Monday.

A rising number of European states said they would send arms directly, prompting pressure from the right-wing opposition Popular Party, which urged Sanchez to "rise to the occasion" and not "hide behind the EU".

"We must respond to a European threat with a coordinated, united European response... and Spain responded immediately," Sanchez told parliament on Wednesday.

The United States, Canada and more than a dozen European countries have so far agreed to Ukrainian appeals for military equipment.

The announcement came a day after Spain said it would send 150 additional troops to Latvia as part of a wider NATO build-up in the Baltic region.

It already has 350 troops in place.

Sanchez said Russian President Vladimir Putin's decision to invade Ukraine was "a brutal attempt to stop the construction of a European space based on values radically opposed to the authoritarianism he represents".