U.S. President Donald Trump on Monday called for a "full and complete" sentence for his former personal lawyer Michael Cohen.

"You mean he can do all of the TERRIBLE, unrelated to Trump, things having to do with fraud, big loans, Taxis, etc., and not serve a long prison term?" Trump said in a pair of tweets.

"He lied for this outcome and should, in my opinion, serve a full and complete sentence," the president added.

Cohen pleaded guilty in August to eight counts of campaign finance violations, tax fraud, and bank fraud. He is scheduled to be sentenced on Dec. 12.

That case was handled by federal prosecutors in New York, rather than the team of special counsel Robert Mueller, who's looking into the alleged Russian interference in the 2016 U.S. presidential election and any potential collusion between the Trump presidential campaign and Moscow.

Last week, Cohen, who has been in discussions with Mueller's team for months, reached a plea deal with the special counsel to a single count of making false statements to Congress about an aborted Trump Tower development project in Moscow, a move that has drawn sharp criticism from the president.

Trump slammed last week Cohen as "a weak person" who was lying to get a reduced sentence, as he defended the legality of his business dealings.

Cohen served as a vice-president of the Trump Organization and special counsel to Trump and previously served as co-president of Trump Entertainment.

In another tweet Monday, Trump praised another longtime associate, Roger Stone, who has also drawn Mueller's scrutiny, citing Stone's pledge that he would never testify against the president.

"This statement was recently made by Roger Stone, essentially stating that he will not be forced by a rogue and out of control prosecutor to make up lies and stories about 'President Trump,'" he wrote. "Nice to know that some people still have 'guts!'"

U.S. intelligence agencies have claimed that Russia was the source of hacked material released by WikiLeaks, an organization that publishes secret information, news leaks, and classified information provided by anonymous sources, in the weeks ahead of the 2016 election that damaged the campaign of Hillary Clinton, then Democratic candidate for presidency.

Mueller's team is reportedly trying to determine whether Stone and other Trump associates had advance knowledge of WikiLeaks' plans.

Stone said last month he is prepared to be indicted but has denied being a conduit for WikiLeaks.

Trump has repeatedly dismissed any collusion between his campaign and the Russians while slamming the Russia probe led by Mueller as a "hoax" or "witch hunt."