The first package of sanctions, announced by Washington earlier in August, include, in particular, the ban on supplies of dual-purpose electronic devices and components to Russia.
However, as of 2:00 a.m. Washington time on Thursday (6:00 GMT) the sanctions, which should come into force after being published in the US Federal Register, the daily journal of the US government, have not been released on the official portal.
The US State Department and the Treasury have not responded to Sputnik's request to specify the date for the sanctions' introduction.
On August 8, the US administration announced a new round of sanctions against Russia due to its alleged use of chemical weapons in the poisoning of the Skripals in the UK city of Salisbury in March.
According to media reports, the second round of sanctions, which might be imposed in November, might include scaling back diplomatic relations between the two countries, suspending flights of Russian airline Aeroflot to the United States and almost complete cessation of US exports to the country. According to the US State Department, Russia could avoid the second round of sanctions by assuring it would not use chemical weapons in the future.
Russia has repeatedly denied involvement in the Skripals case, stressing that London has neither provided evidence nor cooperated with Moscow in investigating the incident.