Sergio Ramos insists the Spain squad are united in the goal of qualifying for the 2018 World Cup - and has backed up Gerard Pique's comments about the pair's "very good" relationship.

Ahead of Friday's qualifier against Albania, the Real Madrid defender spoke about a difficult week for his country following the violence at the Catalan independence referendum last Sunday.

However, while airing his belief that sport and politics shouldn't mix, Ramos hopes the country can now come together to cheer on the national team, as they bid to maintain top spot in Group G and secure a place in Russia next year.

Julen Lopetegui's side sit three points clear of nearest rivals Italy in the standings, with their home tie against Albania followed by a trip to Israel on Monday.

"It is a mistake to mix politics and sport. It has not been an easy week - we must focus on Albania," Ramos told the media.

"We have all been united by the goal of the Albania game and to go one step further for the World Cup.

"It would be my fourth World Cup and it is something that fills me with pride, like being here, in every game, in every training session with Spain."

Ramos was also asked about Pique, who declared his continued commitment to the national team on Wednesday despite being booed by supporters during an open training session earlier in the week.

There was speculation the central-defensive pairing had fallen out over a tweet Barcelona's Pique posted in support of the controversial vote in Catalonia, but Spain's captain dismissed the idea of a rift.

"We have a very good relationship even though we think differently. There should not be any problem between us," Ramos said.