Donald Trump could regulate Google's search results and force them to show different links, according to his top economic advisor.

The new rules would presumably force the search giant to show more positive results about the president. The remarks came just hours after Mr Trump tweeted that it might be "illegal" for Google to show negative stories about him.

Larry Kudlow, the president's top economic adviser, told reporters later that the White House is "taking a look" at whether Google searches should be subject to some government regulation.

It is not clear what form any possible regulation would take, and Mr Kudlow did not provide any further clarification. It has been suggested in the past that Google's ranking is protected by freedom of speech laws, meaning that it would be incredibly difficult for the government to compel the company to change its results to suit the president.

Google has denied the accusations from the president. "Search is not used to set a political agenda and we don't bias our results toward any political ideology," it said in a statement.

In his tweets, Mr Trump said - without offering evidence - that "Google search results for 'Trump News' shows only the viewing/reporting of Fake New Media. In other words, they have it RIGGED, for me & others, so that almost all stories & news is BAD. Fake CNN is prominent. Republican/Conservative & Fair Media is shut out. Illegal?"

He added, again with no evidence, that "96% of results on "Trump News" are from National Left-Wing Media, very dangerous".

A search query on Tuesday morning, several hours after the president tweeted, showed stories from CNN, ABC News, Fox News and the MarketWatch business site, among others.

A similar search later in the day for "Trump" had Fox News, the president's favoured cable network, among the top results.

Google, based in Mountain View, California, said its aim is to make sure its search engine users quickly get the most relevant answers.

"Search is not used to set a political agenda and we don't bias our results toward any political ideology," the company said in a statement.

"Every year, we issue hundreds of improvements to our algorithms to ensure they surface high-quality content in response to users' queries. We continually work to improve Google Search and we never rank search results to manipulate political sentiment."

Experts suggested that Mr Trump's comments showed a misunderstanding of how search engines work.

Google searches aim to surface the most relevant pages in response to a user's query, even before he or she finishes typing.

The answers that appear first are the ones Google's formulas, with some help from human content reviewers, deem to be the most authoritative, informative and relevant.

Many factors help decide the initial results, including how much time people spend on a page, how many other pages link to it, how well it is designed and more.

Steven Andres, who teaches about management information systems at San Diego State University, said people often assume that if you give a computer the same inputs no matter where you are that you "get the same outputs".

But it doesn't work that way, he said. "You're seeing different things every moment of the day and the algorithms are always trying to change the results."