Donald Trump’s former lawyer Michael Cohen has made a surprise court appearance in New York where he has plead guilty to lying to Congress about talks with Russia during the presidential election.

Cohen has appeared before a federal court in Manhattan where he said he lied when he told the US Senate Select Committee on Intelligence that a Trump real estate project in Russia ended in January 2016.

As part of a plea deal with special counsel Robert Mueller, Cohen has now said that those talks with Russia continued until at least June 2016. He says he discussed this at least three times with Mr Trump and other Trump family members.

In 2015, Cohen began exploring the possibility of building a Trump Tower in Moscow. He did so with the help of a longtime business associate, Russian-born developer, Felix Sater.

“I will get Putin on this program and we will get Donald elected,” Mr Sater emailed Cohen, according to the Boston Globe. “Buddy, our boy can become President of the USA and we can engineer it. I will get all of Putins [sic] team to buy in on this.”

In a letter to Congress in 2017, Cohen said: “I assume we will discuss the rejected proposal to build a Trump property in Moscow that was terminated in January of 2016; which occurred before the Iowa caucus and months before the very first primary,” Cohen said in that letter. “This was solely a real estate deal and nothing more.”

Mr Mueller’s team say that Cohen has knowingly lied about the timing, which the lawyer now admits.

“I made these statements to be consistent with Individual-1’s political messaging and to be loyal to Individual-1,” Cohen said in court. “Individual-1” has been previously identified as Mr Trump.

Mr Cohen did not speak after leaving court, however his lawyer said, “Michael Cohen has co-operated and will continue to co-operate.”

Cohen, once one of Mr Trump’s top aides, began talking with the Mueller investigation after he pleaded guilty on August 21 to bank fraud and campaign finance violations in an separate deal with New York prosecutors.

Cohen has spent more than 70 hours talking to Mr Mueller since his August guilty plea.

Mr Trump told reporters his ex-lawyer was a “weak person”, claiming he’s “lying” to get a reduced sentence by making up lies about the Trump Tower Moscow project.

“I didn’t do the project, so we are not talking about doing a project,” Mr Trump said. “What he is trying to do is get a reduced sentence so he is lying about a project that everybody knew about.

“There was a good chance that I wouldn’t have won [the election] in which case I would have gone back into the business, so why should I have lost a lot of opportunities,” he continued. “Even if [Michael Cohen] was right it doesn’t matter because I was allowed to do whatever I wanted during the campaign.”

“When I ran for president it doesn’t mean I can’t do business, I was doing a lot of things when I was running [for president],” Mr Trump said.

Asked why he employed Cohen for 12 years if he was so weak and a liar, Mr Trump replied, “because a long time ago he did me a favour.”

Mr Mueller is investigating whether the Trump election campaign in 2016 colluded with Russian efforts to damage his opponent, Hillary Clinton, and whether Mr Trump had sought to illegally obstruct the investigation. But the span of the investigation also reportedly encompasses Mr Trump’s business dealings.

Mr Trump’s favourable comments about Russian President Vladimir Putin in the election campaign, and since he was elected US President, have come under scrutiny over whether he has any personal or business interest in Russia.

Mr Trump, who was scheduled to meet with Mr Putin in Argentina on Saturday, cancelled the talks, citing the fact that captured Ukraine navy ships and crews had not been returned to their country.

Meanwhile, Cohen's guilty plea comes after Mr Trump submitted written answers to Mr Mueller’s questions.

In August, Cohen pleaded guilty to eight separate charges including tax fraud, false statements to a bank, and campaign finance violations tied to his work for Mr Trump, including payments to porn star Stormy Daniels and former Playboy model Karen McDougal, who both claim they had affairs with Mr Trump.

Cohen is due to be sentenced on those charges on December 12. He is expected to be sentenced to between four and five years in prison in that case however it is unclear if the new guily plea will involve more jail time.

Cohen once said that he would “take a bullet” for Mr Trump but has now promised to “put family and country first” by co-operating with Mr Mueller.

Cohen may be hoping to get a lighter sentence for his earlier guilty plea.