Foreign Minister Murray McCully is "fit and healthy" after surgery but needs time to recuperate, Prime Minister John Key says.
There was speculation ahead of today's Cabinet reshuffle that Mr McCully might be replaced because of his health issues.
"There's no question mark over him," Mr Key told reporters.
"He's taken my advice to have a good recovery, the operation was originally thought to be straightforward but it turned out to be a lot more complex."
Mr Key says Mr McCully has a tough travel schedule ahead of him next year, and he talked to the foreign minister about that.
"I'm confident he will be back on board when Parliament resumes in February."
Mr McCully, 62, had surgery early last month.
It was understood to have involved removing a tumour, which turned out to be benign.