The former head of NATO has claimed that Russia will attempt to influence European parliamentary elections next year.

Anders Fogh Rasmussen, who led the international military alliance between 2009 and 2014, said Monday that Brussels must allocate more resources to challenge interference by Russia.

"I expect the Russians to meddle in the upcoming European parliament elections in spring 2019," Rasmussen told CNBC.

Rasmussen said that between now and the U.S. presidential election in 2020, there are 20 elections to be held in NATO and EU countries and that Russian officials "would do all that they can" to influence their outcome.

He also called for Europe to work more closely with its U.S. counterparts in order to coordinate and enforce more sanctions against Moscow.

"The only language that President Putin understands is the language of power. And that takes firmness, also across the Atlantic," Rasmussen said.

Rasmussen said he wanted to see the fresh round of sanctions targeted at Putin's inner circle.

Prior to joining NATO, Rasmussen was prime minister of Denmark. He now runs his own geopolitical consultancy, Rasmussen Global.