Washington, Sep 13 (IANS): US President Donald Trump on Wednesday signed a decree authorizing sanctions for countries that attempt to influence the November mid-term elections, while his administration denounced possible attempts to do so from Russia, China, Iran and North Korea.

The executive order instructs US intelligence agencies to determine if there are attempts afoot to influence the legislative elections, as occurred during the 2016 presidential vote, and establishes a mechanism for imposing sanctions if interference in any future US election is detected, Efe reported.

"There has been no evidence of a foreign power altering the outcome or vote tabulation in any US election," Trump said in a statement, nevertheless adding that "We're going to take strong action to secure our election systems and the process".

The President has received harsh criticism from the Democratic opposition and from many Republicans for the skepticism with which he has treated the conclusions of the intelligence agencies that Russia attempted to influence the 2016 presidential vote with the aim of helping him win, and for his praise of his Russian counterpart, Vladimir Putin.

National Security Adviser John Bolton, meanwhile, denied on Wednesday that the criticism had influenced the president's decision to take measures to dissuade foreign powers from interfering in the races for both houses of Congress.

"We felt it was important to demonstrate the President has taken command of this issue, that it's something he cares deeply about - that the integrity of our elections and our constitutional process are a high priority to him," Bolton told reporters on Wednesday.

The intelligence agencies have already detected possible "attempts" to interfere with - or intervene in - the November elections by four specific countries.

"It's more than Russia here that we are looking at," National Intelligence Director Dan Coats told reporters on a conference call, specifying that US intelligence agencies are concerned about the ability of Iran, North Korea and China to interfere in the election, and threatening an "automatic response to that".

Trump's executive order declares that a "national emergency" exists linked to possible foreign interference in the US elections, a declaration that creates a legal basis for the future imposition of sanctions linked to that issue.

Within 45 days after any US election, the intelligence services will have to evaluate whether there were attempts by a foreign government or person acting as an agent of another government to interfere with the election, according to the decree.

The Departments of Justice and Homeland Security will then have another 45 days to decide whether or not to impose "automatic" sanctions and the heads of the State and Defense Departments will evaluate whether to levy even more severe punishments.

Bolton said that the US considers interference to be not only attacks on election infrastructure but also the distribution of propaganda and disinformation.

The sanctions would block US financial activities by those implicated in the election interference and those individuals would be prohibited from entering this country.

A wide variety of additional sanctions could be imposed under certain conditions.