Wilshere has committed his future to the north London club alongside fellow internationals Alex Oxlade-Chamberlain, Kieran Gibbs, Carl Jenkinson and Aaron Ramsey.
One name conspicuous by its absence on that list was Walcott, whose contract expires in the summer.
Liverpool and Manchester City are reported to be monitoring Walcott's situation with the England winger holding out for higher wages and a change in position to striker.
Walcott will have been encouraged by the quintet's decision to sign - especially Wilshere - and Wenger is pleased to have retained a British core within the team.
"The plan is to build a team around a strong basis of young players, in order to get them to develop their talent at the club," Wenger said.
"Jack is certainly the best known, the leader of this group - but the other four players are exceptional footballers, and we're very happy that we could conclude their new deals at the same time.
"Gibbs, Jenkinson, Oxlade-Chamberlain, Ramsey and Wilshere represent a core of the squad and it's an extension for a long period for all of them.
"I'm a strong believer in stability and I believe when you have a core of British players, it's always easier to keep them together and that's what we'll try to achieve going forward."
- Sports & Recreation
- Carl Jenkinson
- Kieran Gibbs