MADRID: Spain will send two more US-made HAWK air defence systems to Ukraine in addition to four shipped last week to help it repel Russia's invasion and protect its battered infrastructure, Spanish Defence Minister Margarita Robles said on Thursday.

Last month, Ukraine asked NATO countries for additional help to fend off missile and drone attacks after Moscow struck cities across the country during rush hour, killing civilians and destroying vital infrastructure such as water supply and power stations.

The strikes appeared to be meant as retribution after Russian President Vladimir Putin declared an explosion on the bridge to Russia-annexed Crimea to be a terrorist attack.

Ukraine hails arrival of Western air defence systems

"I can tell you that two more launchers will be sent. This is in response to a very specific request made to us by NATO and Ukraine," Robles told reporters in Madrid.

In addition to the surface-to-air missile launchers, Spain will send a battery of six light howitzers and provide training for Ukrainian howitzer crews, Robles said, adding that Spain was aiding Ukraine because the country is exercising the right to self defence.

The United States is considering sending older HAWK equipment from storage to Ukraine, two US officials told Reuters last month. The interceptor missile equipment is based on Vietnam-era technology, but has been upgraded several times.