WASHINGTON (AP) — Secretary of State John Kerry says he will comply with “whatever responsibilities” he has to Congress in answering questions about the attack on the U.S. diplomatic compound in Benghazi, Libya. But he was silent on whether he would appear at a May 21 hearing under subpoena.

Secretary of State John Kerry looks down as he adjusts the microphones before speaking about the situation with Ukraine and Russia from the State Department in Washington, Thursday, April 24, 2014. Kerry is accusing Russia of failing to live up to commitments it made to ease the crisis in Ukraine. (AP Photo/Jacquelyn Martin) AP Photo/Jacquelyn Martin

Secretary of State John Kerry looks down as he adjusts the microphones before speaking about the situation with Ukraine and Russia from the State Department in Washington, Thursday, April 24, 2014. (AP Photo/Jacquelyn Martin)

In his first public comments on the matter, Kerry said Tuesday that he was surprised to have been subpoenaed to testify before the House Committee on Oversight and Government Reform because the panel had not first invited him to appear. Kerry aides have said that he has previously scheduled travel plans and will be in Mexico on May 21.

Kerry did not mention his travel plans but said the State Department would respond because it has “absolutely nothing to hide.”