Homeland Security Secretary Kirstjen Nielsen promised that the federal government would do all it could to prevent Russians from hacking future elections, but stopped short of guaranteeing that those measures would be effective.
“I feel secure that we are and will continue to do everything we can to help state and locals secure their election infrastructure,” Nielsen said on Tuesday, avoiding answering a question about whether the U.S. voting system is hacker proof.
The DHS secretary’s comments at the annual RSA cybersecurity conference in San Francisco come after members of the U.S. Senate Intelligence Committee urged Nielsen and the DHS to speed up efforts to secure the nation’s elections, according to the New York Times. In September, the DHS notified 21 U.S. states that Russia had attempted to hack their voting systems prior to the last presidential election.
Suspected Russian hackers were only able to breach the voting system in Illinois, but they were unable to modify any votes, the Times report said.
Nielsen’s failure to directly answer the question on stage on Tuesday highlights the challenges the federal government faces in dealing with increased cybersecurity threats from nation-states. She and President Donald Trump “are committed” to preventing “any meddling” in future elections, Nielsen said, but that more work must be done.
“We have the right tools, but we need to do more in terms of the partnerships,” Nielsen said about the help that the DHS has given states to secure their elections.
Complicating matters is President Trump’s reluctance to acknowledge the Russian government’s role in tampering with the 2016 presidential election by allegedly spreading fake news and propaganda on social media services like Facebook.
On Monday, the Trump walked back imposing additional sanctions against Russia that U.S. United Nations Ambassador Nikki Haley announced the day before for its support of Syrian leader Bashar al-Assad following a recent chemical weapon attack in Syria.
White House Press Secretary Sarah Sanders explained on Tuesday that the White House is still evaluating the sanctions, according to USA Today.
Get Data Sheet, Fortune’s technology newsletter.
Nielsen said that her department is not responsible for combating the spread of fake news and misinformation by other nations and that it is instead focused on the nation’s infrastructure.
