House Speaker John Boehner (R-Ohio) on Thursday stepped off the sidelines and called for President Obama to address lingering questions about the deadly attack on the U.S. consulate in Libya that left an American ambassador dead.

In a lengthy letter to Obama that inserted the top Republican lawmaker squarely into the escalating political controversy surrounding the attack, Boehner criticized shifting stories about the nature of the attack and questioned whether the administration had given enough attention to calls for better security at the consulate. The letter came one day after leaked emails rekindled the debate about who knew what and when about the circumstances of the attack that killed Ambassador Christopher Stevens and three other Americans on the anniversary of the Sept. 11, 2001 attacks.