National Football League officials are looking at staging regular-season games in Germany and Mexico and adding more games in London in a bid to boost global growth.

According to a posting on the NFL's website, the league is building the roots of a season-ticket fan base in London with an eye to going from three to four Wembley Stadium games next year and targeting 2017 for games in Germany and Mexico.

Mark Waller, NFL International executive vice president, said the league likely would have staged four regular season games in London this year were it not for England hosting the Rugby World Cup in September and October, the first two months of the NFL campaign.

But Waller also said the NFL was on track for a potential team in London by 2022 as all three 2015 games are sold out.

In addition, 40,000 fans bought tickets for all three of this year's Wembley games, most of them people from the London area who did the same last year -- buying habits the NFL sees as the start of the season-ticket support an England NFL club would need.

The NFL is looking at staging the 2017 Pro Bowl all-star game in Brazil and studied venues in the Mexico City area earlier this month, according to the report, which also named Frankfurt and Dusseldorf as most likely to host a German NFL regular-season contest with Berlin and Munich also being considered.

In addition, the league is examining the feasibility of staging a portion of a team's pre-season training camp and possibly some pre-season scrimmages in Mexico.

Regarding China, the report said the NFL focus in on media rights, especially digital rights with the league seeking an online content distributor.

"The work we're doing now is to ask, 'How do we accelerate the agenda in Mexico, Canada and China?' Those would be our next stage," Waller said. "After those, where should be our focus? I think we've concluded that Brazil and Germany are the next two frontier markets."