The tour, the first in six years by a test-playing nation to Pakistan, was throw in doubt last week when a terrorist attack on a bus killed 47 people in Karachi.
“The tour is going ahead and we leave tonight,” Whatmore said via telephone from Harare before reconfirming his belief the tour would be successful and that security measures put in place by Pakistan will be adequate.
Zimbabwe will play two Twenty20 internationals, starting on May 22, and a three-match one-day series that begins four days later. All the matches are in Lahore.
Zimbabwe Cricket released a statement on Thursday saying a decision had been reached not to tour on the advice of the country's supreme sports regulatory authority, the Sports and Recreation Commission (SRC).
The SRC cited concerns over the safety of the squad.
However, just minutes later the statement was withdrawn and Zimbabwe Cricket spokesman Lovemore Banda said discussions were still ongoing.
It is understood that concerns also emanated from the players themselves, some of who were reluctant to travel but have now been persuaded to tour after additional security measures were announced by the Pakistan Cricket Board (PCB).
Those were still deemed not good enough for the International Cricket Council, though, which released a statement on Sunday saying they would not be sending match officials for the series.
They cited a report by a security consultant who advised against sending a team of officials to the country.
The ICC said the PCB would have to appoint its own officials, but that this would not affect the status of the games which would remain as full internationals.
Zimbabwe are the first test-playing nation to tour Pakistan since a 2009 gun attack on Sri Lanka's team bus in Lahore left six Pakistani policemen and a van driver dead. Some players and a local umpire were injured.
(Reporting by Nick Said, editing by Ed Osmond)
