New Zealand skipper Kane Williamson is confident of regaining full fitness and recover from an "ongoing niggle" before the start of the two-Test series against England beginning November 21.

Williamson is not part of the ongoing five-match T20I series because of a hip injury and Tim Southee is leading the Black Caps in his absence.

“It's been an ongoing niggle, really," he told Sky Sports NZ. "That comes at goes. It is settling, which is nice.”

“A lot of (the last few months) has been rehab to get the hip right,” he explained. “I had a four-dayer recently (for Northern Districts, against Canterbury), and there's a gap between this series and the first Test, so it's basically training going into it.

“A lot of it is the mindset. So trying to get that right, trying to prepare as well as you can to give yourself the best chance,” he added.

Currently, the five-match T20I series is tied at 2-2 with the series decider to be played on Sunday.

The first Test will be played at the Bay Oval from November 21-25 and the second will be held at Seddon Park from November 29-December 3.