ELMAU CASTLE, June 27 (AFP) - The United States is planning to send Ukraine sophisticated anti-aircraft missiles to defend against Russian attacks, US national security adviser Jake Sullivan said on Monday (Jun 27).

"I can confirm that we are in fact, in the process of finalising a package that includes advanced air defence capabilities," Sullivan told reporters in Germany, where President Joe Biden was attending the G7 summit.

Sullivan said Biden had told Ukrainian President Volodymyr Zelenskyy - who joined the G7 talks by video link - that the United States was preparing shipment of "advanced medium- and long-range air defence capabilities".

Sullivan said additional aid being prepared due to "urgent need" also included artillery ammunition and counter-battery radar systems, which are used to pinpoint the source of enemy artillery firing.

In his address to the G7, Zelenskyy spoke about a missile attack by Russia against a residential area of the capital Kyiv on Sunday and told world leaders that he wanted "additional air defence capabilities that could shoot down missiles out of the sky", Sullivan said.

According to a US source, who asked not to be identified, Biden "has made the procurement of advanced air defence systems for Ukraine a priority".

An announcement is "likely this week" on the purchase of NASAMS, an "advanced medium- to long-range surface-to-air missile defence system", as well as other weaponry to help Ukraine fight Russia's invasion.

Zelenskyy has pleaded for more powerful defences against Russian air attacks since the start of the invasion in February.

With Russian aircraft and cruise missiles bombing Ukrainian troops and civilians daily, Zelenskyy initially focused on his rallying cry of "close the skies" with a request for Western countries to send war planes to Ukraine.

After the United States and European allies made clear that sending planes was too risky, potentially drawing them directly into the conflict against Russia, focus pivoted to surface-to-air missiles.

Ukraine has a variety of these weapons, including the powerful Soviet-designed S-300 system.

The NASAMS, built by Raytheon in the United States in partnership with Norway's Kongsberg Defence and Aerospace, has been sold in 12 countries, according to the company website.

Germany has promised to send Ukraine an Iris-T air defence shield system which it said was capable of protecting a large city from air raids.