President Joe Biden on Thursday signed an executive order that is his final stab at shoring up America’s cyber defenses after a damaging string of cyberattacks on federal networks that US officials have blamed on Chinese and Russian operatives.

President Joe Biden issued an executive order Thursday aimed at strengthening U.S. cybersecurity defenses and cracking down on foreign hackers targeting critical infrastructure. The order establishes mandatory cybersecurity standards for government contractors,

Thursday’s order includes provisions requiring government contractors to show they are meeting federal security standards.

Rules include tougher standards to ensure software is more secure and bolster sanction authority against likes of Beijing.