White House is not in loop of probes by FBI on Hillary: Josh Earnest

The White House is not in loop of sensitive probes conducted by career prosecutors with the FBI's assistance, a top US official has said.

White House Press Secretary Josh Earnest said the White House stays out of providing any guidance or influencing any sort of criminal investigation.

His remarks came in the wake of FBI Director James Comey's decision to re-open investigations into the alleged email scandal of Democratic presidential nominee Hillary Clinton.

For the past few days, Comey is under fire from the ruling Democratic party for his decision.

"There's a reason he was appointed. Obama continues to have confidence in his ability to do that job," Earnest told reporters while travelling with Obama from Washington to Ohio for various election rallies in support of Clinton.

Asked what advice Obama will eventually offer to his successor, Earnest said he cannot say right now.

"The president's not just having a good time, he looks like he's having a good time. I think he's mindful of the fact that over the course of this week this will essentially be the last big campaign swing of his political career," he said.

"So I think he's looking forward to making a spirited case on behalf of Secretary Clinton as well as Democrats up and down the ballot. Part of this is an indication of exactly how big he thinks the stakes are in this election," Earnest said.

In the last week of the presidential election to elect his successor, Obama is on a campaign blitz addressing rallies in key battleground States like North Carolina, Ohio and Florida.

On reports of an FBI investigation into Trump's connection to Russian associates, Earnest did not confirm the probe.

At the same time he reiterated the importance of the White House staying out of the Department of Justice and FBI's way in their prosecutorial and investigative decisions, whether there's an election around the corner or not.

Earnest brought up the recent intelligence findings about Russian involvement in cyber breaches, but did not connect them to Trump.

"The president is certainly mindful and monitoring threats to our political system that could be emanating from Russia," he said.

"But any sort of criminal investigation that is conducted is one that is led by career prosecutors with the assistance of the FBI, they are going to follow the facts where they lead, they will carefully examine the evidence, and they will make the prosecutorial and investigative decisions that are required to reach a conclusion. That is something that they will do without any guidance or influence by the White House," Earnest said.

On the release of FBI information on the Clinton-era pardon of Mark Rich, Earnest said he did see the tweet from the FBI records vault.

"I did see the tweet from the FBI Records Vault. That's the first time I've ever noticed a tweet from the FBI Records Vault," he said.