Defending champions Great Britain, Argentina and France gatecrashed their hosts' Davis Cup parties to edge closer to the semi-finals on Saturday.

A North American-led campaign to ban Russia from the Rio de Janeiro Olympics has opened up an international divide on how to deal with the doping scandal engulfing Russia.

Portuguese Finance Minister Mario Centeno pinned his colors to the mast, donning a green and red scarf as his countrymen lifted the European Championship trophy.

Brazil's interim president will hold an emergency meeting with cabinet ministers Friday to bolster security for next month's Olympics, officials said after a suspected terrorist attack in the French city of Nice.

"We think we will have to intensify the security monitoring system. We will have to increase the number of checkpoints and controls," Defense Minister Raul Jungmann told TV station Globo.

Barcelona star Neymar was as expected named in the Brazil squad for the Olympics football tournament on Thursday as well Paris Saint Germain defender Marquinhos.

Pop superstar Katy Perry re-emerged Friday after a quiet spell with a song of unity as part of the television coverage of the 2016 Rio Olympics.

The singer -- one of the most successful artists of her generation -- offered her first new music since her blockbuster 2013 album "Prism" with the song "Rise."

France Davis Cup captain Yannick Noah, riders at the Tour de France and golfers at the British Open led tributes Friday from the world of sport to the victims of the Nice terror attack.

France was informed of a planned terror attack on its team at the Rio Olympics, according to the head of military intelligence cited in an official document.

Four NBA stars issued a plea for an end to the violence in America on Wednesday with LeBron James calling on athletes in all sports to use their influence make their cities safer.

James delivered his message of hope at the opening of the annual ESPN awards show, taking the stage alongside fellow NBA players Dwyane Wade, of the Chicago Bulls, Chris Paul, of the Los Angeles Clippers and Carmelo Anthony, of the New York Knicks.

The Davis Cup quarter-finals take place this weekend but are missing the superstar pulling power of Novak Djokovic and Andy Murray and potentially overshadowed by Rafael Nadal's last-ditch attempt to get to the Rio Olympics.