Pakistan 'have underperformed' says Agha after T20 World Cup exit
Pakistan were knocked out on net run rate despite beating Sri Lanka in their final Super Eights match in Kandy on Saturday.
"We have underperformed in the whole tournament," Agha told reporters.
"We are out of the semis due to our failure in decision-making in pressure situations."
Opener Sahibzada Farhan became the only player to score two hundreds in the same T20 World Cup as Pakistan posted 212-8.
But they failed to restrict Sri Lanka to 147 and New Zealand went through to the semi-finals.
"Farhan was outstanding in the tournament but none of the other batters could come up to expectations," said Agha, who only managed 60 runs in seven tournament matches.
Sri Lankan skipper Dasun Shanaka hit 76 not out off 31 balls with eight sixes as Sri Lanka scored 207-6 to lose by five runs.
A rained-off Super Eights opener against New Zealand and a defeat to England left Pakistan needing to beat Sri Lanka by a massive margin to advance.
"(Head coach Mike) Hesson and I take the responsibility as we selected the eleven for the matches," said Agha, who added he would not make an immediate call on whether to stand down as captain.
"I will go back and take some time to decide," he said.
"Because at this point of time stepping down would be an emotional decision."