The head of the Russian cyber-security company Kaspersky Lab has said he will testify before the U.S. House of Representatives, a day after government agencies were ordered to stop using the firm’s products.

The U.S. government has been given one month to map their use of Kaspersky products and three months to begin their removal, the U.S. Homeland Security Department (DHS) said in an online statement on Wednesday.

Last July, the Trump administration already removed Kaspersky from the list of approved state agencies’ software vendors, citing concerns Russian authorities could infiltrate U.S. government networks using Kaspersky’s anti-virus products.

The Reuters news agency cited the U.S. House Committee on Science, Space and Technology as saying on Thursday that it had invited Eugene Kaspersky to testify on Sept. 27. alongside an unspecified number of U.S. government and private sector cyber experts.

Kaspersky, who founded the company in 1997, has denied ties to Russian security and intelligence agencies since suspicions surfaced in 2015. But he has acknowledged he graduated from a KGB-sponsored school and worked for the Soviet Defense Ministry.

Kaspersky said he had repeatedly offered to testify before the U.S. Congress to address any questions about his firm.

“I have accepted an invitation to testify before US House of Representatives & address allegations about KL [Kaspersky Lab],” Kaspersky wrote on Twitter late on Thursday. “Hope to get expedited visa.”