Pakistan failed to qualify for the semi-finals of the marquee tournament, losing three successive group phase matches.
Adding insult to injury was a bruising six-wicket defeat to arch-rivals India that drew fierce criticism of the under-performing players and the team management.
Waqar said the team will not improve unless the whole system is changed and made transparent. At a press conference outside the Pakistan Cricket Board (PCB) office in Lahore, Waqar said that "apparent makeup surgery will not work".
"I apologise for the team's performance in the T20 World Cup," he was quoted as saying by nation.com.pk, but warned against any knee-jerk reaction.
"The matter will not be solved, if we blame single individuals, whether it's me, (Shahid) Afridi or the PCB chairman. We have to find the real inner problems."
He said there is a need to sit down and talk to find long-term solutions, but added that he's willing to resign if that is believed to be the solution.
"If things will improve if I leave, then I am ready to go home," he said.
Waqar denied internal rifts in the dressing room and said it has been a difficult time for him as well.
"There is no politics in the team or any grouping. Our performance is bad and so we don't have time for any groupings," he said.
"The nation's anger is justified because we did not perform well. But now is the time to make things open and clear, the time of hiding actual issues has passed. I was hurt by the team's losses."
The former pace legend said that being deprived of cricket at home is one of the reasons the national team has struggled.
"Although we call UAE our home but playing at home makes a huge difference and this leads to emergence of new talent," he said. "Our domestic structure has weakened because we have not played cricket in Pakistan."
The national cricket team coach said that his future is not necessarily linked to cricket.
"Cricket is not game of stars, it is a game of heroes," he said while responding to a question.
"My future is not linked to cricket. I have been the coach before and I was liked by everyone. So it is not me, or a single person, it is about the system."