The league has been heavily criticised for its handling of a recent series of assaults involving players.
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Waller says they are continuing to deal with the issue as Wembley prepares to host Oakland Raiders v Miami Dolphins.
"You don't take a holiday from an issue like that," Waller told BBC Sport.
"It is a huge, serious issue that has the potential to undermine things that we do and things that we try to accomplish," he said ahead of Sunday's fixture.
"I have spent as much time here on this issue, making telephone calls back to the US.
"It is a critical issue for us and one that we are going to get right. We are not looking for a holiday from it, we are looking to solve it."
Last week, NFL boss Roger Goodell apologised for his mistakes, particularly in dealing with the abuse case involving former Baltimore Ravens running back Ray Rice.
Goodell initially banned Rice for two games after video emerged of him punching Janay Palmer, his then-fiancee, now wife, in the face and knocking her out in a lift in Atlantic City in February.
It was only after a video was posted online on 8 September that Rice was released by the Ravens and banned from the league indefinitely.
In a separate incident, Adrian Peterson, a star running back for the Minnesota Vikings, was arrested and charged with child abuse earlier this month.
Waller rejected suggestions that Goodell's position was in danger and reiterated the league's pledge to implement new personal conduct policies.
"We need to do a better job on all of our conduct policies and all those that impact on social behaviour," he added.
"We need to be way more publicly engaged in those debates and helping solve them and using the access and assets that we have got to a massive fanbase to communicate the core of those issues and we need to do a better job.
"I am absolutely confident that we will move forward."
The NFL's London fixture is not being used to distract from the issue of domestic abuse within the sport, the NFL's executive vice-president of international, Mark Waller, has said.