The 28-year-old, who has had an inconsistent start to the season with the Swans, was named as the nation's skipper by manager Chris Coleman after deciding to strip Arsenal midfielder Aaron Ramsey from the role.
"I'm pleased to get the captaincy. It's obviously a great honour and once I meet up with Wales I'll speak more to the gaffer and know a bit more about what he wants from me," the South Wales Evening Post quotes Williams as saying.
"I've captained the team before so it's no great change. The boys know me and I know them so we'll go into a massive week and the most important thing, irrespective of who the captain is, is a win, especially in that first game. It's a nice little boost for me at a time when things haven't been going well."
Wales will take on Scotland and Croatia over the two-week international period.