Duffy, 30, has played ten ODIs, and taken 18 wickets at an average of 25.94 and economy of 6.25. He recently took four wickets in two ODIs, and eight in three T20Is against Sri Lanka in a home series that ended earlier in January.
New Zealand then play a Champions Trophy warm-up game against Afghanistan on February 16, followed by the tournament opener against Pakistan on February 19, with both those fixtures also being in Karachi.
They then travel to Rawalpindi to play their second Group A fixture against Bangladesh on February 24, followed by a trip to Dubai for the game on March 2 against India, who are not playing any of their Champions Trophy matches in Pakistan because they did not get government clearance to travel.
New Zealand squad for tri-series and Champions Trophy
Mitchell Santner (capt), Michael Bracewell, Mark Chapman, Devon Conway, Lockie Ferguson, Matt Henry, Tom Latham, Daryl Mitchell, Will O’Rourke, Glenn Phillips, Rachin Ravindra, Ben Sears, Nathan Smith, Kane Williamson, Will Young, Jacob Duffy (tri-series only)