Ukraine's President Volodymyr Zelensky landed in Spain Monday for talks with Prime Minister Pedro Sanchez with the pair due to ink a deal increasing Madrid's military aid to Kyiv.

As he touched down at Madrid's Barajas airport at 1000 GMT, Zelensky was met on the tarmac by King Felipe VI and then headed straight into the Spanish capital to meet Sanchez where the two leaders were to sign a security agreement.

The visit comes as Ukraine battles a Russian ground offensive in the northeastern Kharkiv region which began on May 10 in Moscow's biggest territorial advance in 18 months.

With the Russian assault now in its third year, Ukraine has been pleading for more weapons for its outgunned and outnumbered troops, notably seeking help to address its lack of air defence systems.

After their meeting, the two leaders were expected to hold a news conference, Sanchez's office said.

Zelensky was then expected at the Royal Palace for talks followed by "a lunch in his honour" hosted by King Felipe and Queen Letizia, a palace statement said.

Zelensky had been due to visit on May 17, but postponed his trip after Russian troops began a major assault on the Kharkiv region.

According to El Pais newspaper, Monday's deal would include 1.1 billion euros worth of military aid and include new Patriot missiles and Leopard tanks.

Zelensky has already signed bilateral security agreements with several countries including France, Germany and the UK.

So far, Madrid has only provided limited military aid to Kyiv.

According to the Kiel Institute -- which tracks weapons pledged and delivered to Ukraine since the Russian invasion -- Spain has so far committed 330 million euros in military aid, making it a small contributor on a European level.

By comparison, Berlin, Paris and Rome have committed 18.61 billion, 5.65 billion and 1.0 billion euros respectively, while London's contribution stands at 9.22 billion, the figures show.

In April, Spain pledged to send an unspecified number of Patriot air defence missile systems to Ukraine. It has also sent 10 Leopard tanks.

Although the Ukranian leader was in southern Spain for an EU summit in October, it was his first official visit to Spain since taking power in 2019.

Last week, Sanchez told parliament the two nations were also preparing to sign a bilateral cooperation agreement.

"As soon as the situation on the front allows, we will sign an agreement with Ukraine that will increase economic, social and institutional cooperation between our countries," he said.