Foster, in his eighth season as a Hansen deputy, told reporters in Auckland on Wednesday that he was keen to step up.
"If you're asking me what happens after [the World Cup], then we'll have to wait and see," the former Chiefs coach said.
"I'm absolutely committed to this team. This is my eighth season, and I'm keen to carry on. I'm excited about an opportunity to put my name in the ring as a head coach, but that's the future."
