The U.S government is considering employing visa restrictions to prevent Chinese nationals from attending the popular summer hacking conferences in Las Vegas. The move is part of a broader effort to prevent Chinese cyber espionage.

Earlier this week, the United States charged five Chinese military officers with hacking into U.S. nuclear, metal and solar companies to steal trade secrets. The indictment was the first criminal hacking charge that the United States has filed against specific foreign officials.

China has denied the charges made by the US grand jury indictment, saying they were “made up” and would damage trust between the two nations.

Washington could use such visa restrictions and other measures to keep Chinese from attending the August Def Con and Black Hat events to maintain pressure on China.

Organizers of the two conferences denied any knowledge of the visa restrictions, but said that limiting participation from China was a bad idea.

Jeff Moss, founder of both Def Con and Black Hat, posted his thoughts on the visa restrictions on Twitter: “First I have heard of it, boarding flight to D.C. now. I don’t think it helps build positive community.”

Chris Wysopal, a Black Hat review board member, said restricting access would have little influence on hacking as the talks from both conferences are videotaped and sold on DVDs or posted on the web.

At Black Hat, an employee of Chinese security software maker Qihoo 360 is scheduled to speak on software vulnerabilities in font scalers and two researchers with Chinese University of Hong Kong are expected to speak on hacking social media. Def Con does not have any Chinese nationals on its roster.

US agencies are considering a range of options if China does not acknowledge and curb its corporate cyber espionage.

The Wall Street Journal reported late on Friday that US options to curb hacking could include releasing additional evidence about how the hackers conducted their alleged operations, and imposing other business and financial restrictions on those indicted or people or organizations associated with them.