Great Britain take on the United States in the Davis Cup World Group first round, while Switzerland's title defence looks set to come to a premature end.

Andy Murray will be in action in Glasgow as Great Britain meet the USA, who will be led by John Isner, for the second straight year.

Murray helped Great Britain to a 3-1 win in San Diego a year ago, with the hosts surprisingly opting for a clay surface at Petco Park.

The two-time grand slam winner said it was a big ask for his team to repeat that feat.

"It helps [to have won last year]. I know Isner wasn't able to play," Murray was quoted as saying by the Davis Cup website.

"Also it was on clay and I did say at the time I thought it was a strange surface choice, which I thought favoured us, really.

"Obviously an indoor hard court is a quite neutral surface for everyone. It will be tough if they are all fit and well. It will be a tough one for us to win but it’s possible."

At 111, James Ward is Great Britain's second singles player – while the US have Isner and the in-form Donald Young.

Switzerland face an even tougher task as they begin their title defence against Belgium in Liege.

Roger Federer and Stan Wawrinka are both absent, leaving Yann Marti (292) as their highest-ranked singles player.

With David Goffin part of the Belgium team, they are likely to be hard to stop on the indoor hard courts.

Elsewhere in the first round, Gilles Simon and Gael Monfils will lead France into their tie against Germany in Frankfurt.

The winner of that tie will face either Great Britain or the USA.

There are also fierce rivalries taking place in both Europe and South America.

Novak Djokovic will lead Serbia into action against a Marin Cilic-less Croatia in Kraljevo.

In Buenos Aires, where clay is unsurprisingly the surface of choice, Argentina take on Brazil in what should be a hard-fought tie.

Elsewhere, Australia travel to Ostrava to take on the Czech Republic – who are without Tomas Berdych.

Fabio Fognini and Andreas Seppi lead Italy into a meeting with Kazakhstan in Astana, while Milos Raonic and Kei Nishikori will take centre stage as Canada take on Japan.