Secretary of State Mike Pompeo said Saturday the State Department intends to follow the law in the House impeachment investigation and vigorously defended President Donald Trump, dismissing questions about the president’s attempts to push Ukraine and China to investigate a Democratic political rival.

The Trump administration and House Democrats often disagree about what the law requires, leaving open the question of how Pompeo may interpret Democrats’ demands for key information about Trump’s handling of Ukraine.

Pompeo, speaking in Greece, said the State Department sent a letter to Congress Friday night as its initial response to the document request and added, “We’ll obviously do all the things that we’re required to do by law.” He has allowed Democrats to interview a series of witnesses next week. Among them is Gordon Sondland, the U.S. ambassador to the European Union, another key figure in the probe.

Pompeo has become a key figure in the Democrats’ investigation. He was on the line during the July phone call in which Trump pressed Ukrainian President Volodymyr Zelenskiy to investigate former Vice President Joe Biden and his son, Hunter — sparking a whistleblower complaint and now the impeachment inquiry.

On Saturday, Pompeo did not back off his defense of Trump’s call with Ukraine.

“There has been some suggestion somehow that it would be inappropriate for the United States government to engage in that activity and I see it just precisely the opposite,” he said.

Pompeo made clear that the State Department had yet to turn over any document, but intended to follow a proper review. And he said he would do so faster than the Obama administration.

“I remember precisely once when I was on that side and we were looking for documents, I remember precisely how long it took for those documents to come across,” he said in an apparent reference to his experience as a congressman during the investigation into the 2012 attack on the U.S. mission in Benghazi, Libya.

“We’re going to beat that. We’re going to be more responsive than the Obama administration was in the years that preceded this particular Congress,” he said.

Lawmakers are focused on Trump’s efforts to push Ukraine to investigate the Bidens. A whistleblower complaint said that Trump sought to use military assistance for Ukraine as leverage to push the newly elected Zelenskiy to launch an inquiry into the 2020 Democratic hopeful.