The State Department announced on August 8, 2018 that the Trump administration decided it will be imposing further sanctions on Russia. This round of sanctions would be imposed under the Chemical and Biological Warfare Act of 1991 as the U.S. has accused Russia for the March 2018 poison attack on former Russian agent Sergei Skripal and his daughter in the U.K.
The first set of sanction will target specific U.S. exports to Russia that could have military use. Unless Russia takes certain steps in response to the initial round of penalties, Congress would need to impose a second, more stringent round of sanctions on Russia.
Following a 15-day Congressional notification period, this round of sanction will likely take effect on August 22, 2018.