Zimbabwe Cricket (ZC) released an official statement saying the tour would not go ahead following recent militant violence that has revived fears after a deadly attack on the Sri Lankan team bus in 2009.
But the ZC spokesman Lovemore Banda then issued a rapid apology, saying the abandonment was not confirmed.
"The executive and the board are in a meeting right now and we are waiting for their decision," Banda told AFP by telephone, without explaining the earlier statement.
Pakistan has been desperate to regain its status as an international cricket venue, but security concerns rose further this week when gunmen attacked a passenger bus and killed at least 43 people in the southern city of Karachi.
Zimbabwe are due to arrive on May 19 and play two Twenty20 internationals on May 22 and 24 and three one-day internationals on May 26, 29 and 31.
All five matches would be played in the eastern city of Lahore after Zimbabwe refused to play in Karachi. Zimbabwe Cricket said in its first statement:"The decision not to tour at this time has been taken after considering the advice from the country's supreme sports regulatory authority, the Sports and Recreational Commission (SRC)."
An advance party visited Pakistan last week and expressed confidence that the tour would go ahead.
Zimbabwe this week announced its 16-man squad, but a private daily paper on Thursday said the team should not be put in danger.
"One thing is very clear; Pakistan is not a safe destination to travel to," the Daily News said. "Pakistan is on fire at the moment."
Bangladesh have backed out twice after initially agreeing to tour, although Pakistan have managed to host minor teams Afghanistan and Kenya.
