President Donald Trump rallied right-wing activists Saturday with a speech offering conservative red meat on immigration, trade and the threat of "socialism" as he sought to move on from a bruising week in domestic and international politics.

"We believe in the American dream, not in the socialist nightmare," he said to boisterous applause from hundreds of supporters at the annual Conservative Political Action Conference (CPAC) near Washington.

"America will never be a socialist country," Trump added in a mammoth two-hour speech that seemed to draw energy from the fervent reception offered by some of his influential supporters in the room.

It was his first public appearance since coming home empty-handed, and to criticism from all sides, after a nuclear-disarmament summit with North Korea's leader Kim Jong Un. He told CPAC the meeting was "very productive" -- but that he would not "make a deal just for the sake of doing it."

The White House is also smarting from explosive testimony on Capitol Hill by Trump's former lawyer and fixer on Wednesday that branded him a cheat and a racist.

Trump, often speaking in mocking tones, portrayed the Green New Deal climate strategy touted by the left of the Democratic party as a socialist plan that will devastate the fossil fuel and automotive industries.

He said progressive healthcare policies would "lead to colossal tax increases" -- and accused the Democrats of having "totally abandoned the American mainstream" on issue such as immigration and abortion.

With the federal investigation into possible collusion between the Trump campaign and Russia reportedly approaching its conclusion, Trump again berated Special Counsel Robert Mueller's team as partisan hacks out to get him, adding that "these people are sick."

His voice dripping with sarcasm, he suggested that his call in summer of 2016 for Russia to find and release Hillary Clinton's emails was a joke that had been obtusely taken at face value by the media.

On the foreign front, Trump repeated his claim that the last Islamic State group fighters in Syria would be captured or killed imminently -- "as of tomorrow" -- after on Thursday telling US troops "we just took over" 100 percent of the caliphate. Two weeks earlier Trump had declared the fall of the so-called caliphate would be announced "over the next 24 hours."

He railed against Chinese tariffs on American goods and said the US loses $500 billion a year to the world's second biggest economy -- "such a disaster."