A bitter feud between US President Donald Trump and top Democrat Nancy Pelosi boiled over at his State of the Union speech on Tuesday, with Trump snubbing her outstretched hand and Pelosi ripping apart a copy of his remarks behind his back.

Trump avoided the subject of his impeachment drama in a pugnacious 80-minute speech, but the scars from the battle were evident with fellow Republicans giving him standing ovations while rival Democrats for the most part remained seated.

The Republican-led Senate was expected to acquit him on Wednesday of charges he abused his powers and obstructed Congress.

Seeing Pelosi, the US House of Representatives speaker, for the first time since she stormed out of a White House meeting four months ago, he declined to shake her outstretched hand as he gave her a copy of his remarks before starting his speech.

Having not spoken to Trump since their last meeting, Pelosi appeared to be taken aback. She avoided citing the customary "high privilege and distinct honor" that usually accompanies the speaker's introduction of the president to Congress.

"Members of Congress, the President of the United States" was all she said in introducing Trump.

When his speech ended, Pelosi stood and tore up her copy of the remarks he had handed her, later telling reporters it was "the courteous thing to do, considering the alternative."

It was a sign that little legislative progress should be expected over the next year. The impeachment case has intensified bitter feelings between Trump and Pelosi that have existed throughout his presidency.

As he began the speech, Republicans from both houses of Congress chanted "four more years" while he stood at the lectern in the chamber of the House with a presidential election almost exactly nine months away.

Democrats sat silently and some could be seen shaking their heads as Trump declared, "The state of our union is stronger than ever before."

Pelosi, who dropped her opposition to impeachment and allowed Democratic lawmakers to seek the charges against him, sat stoically and grim-faced behind Trump and paged through a paper copy of his speech.

Trump entered the chamber with Democrats experiencing some measure of chaos after technical glitches delayed the results of voting in Iowa on Monday as the party seeks a nominee to face the incumbent Republican.

Trump presented himself as a big improvement over Democratic President Barack Obama, whom he succeeded three years ago, saying he had bolstered US economic growth and increased jobs.

"In just three short years we have shattered the mentality of American decline and we have rejected the downsizing of America's destiny," he said.

The House impeachment managers, acting as prosecutors in the Senate impeachment trial, were seated together at the front of the Democrats' section.

HEALTHCARE AN ISSUE

Many House Democratic women wore white for a second year in a row, a sign of the suffragist movement that won women the right to vote 100 years ago. Several Democratic lawmakers refused to attend the annual speech to protest Trump, such as liberal firebrand Alexandria Ocasio-Cortez.

Trump, using the speech to lay out his vision for a second four-year term, said a Democratic plan to expand government-funded health insurance amounted to a "socialist takeover" that would bankrupt the country, cut benefits for those who have them now and provide care to illegal immigrants.

Democratic presidential candidates and many lawmakers have proposed healthcare plans that would be run by the government, a sharp departure from the current, private system in which millions of Americans receive medical insurance from their employers.

Trump's lack of a healthcare plan has left him open to criticism that he has not put enough work into finding a way to reduce rising insurance costs that burden middle-class Americans.

"We will never let socialism destroy American healthcare!" Trump said.

Democratic women stood and chanted "HR 3" - a reference to a Democratic bill that would lower drug costs.

In the Democratic response to Trump's speech, Michigan Governor Gretchen Whitmer said in excerpts of her remarks: "Democrats are trying to make your healthcare better. Republicans in Washington are trying to take it away."

Trump offered an upbeat portrayal of his presidency in hopes of persuading Americans to give him another four-year term in the Nov. 3 election.

He saluted surprise guest Juan Guaido, the Venezuelan opposition leader, and made cancer-stricken conservative talk radio host Rush Limbaugh an immediate recipient of the presidential Medal of Freedom, Trump's wife Melania pinning the ribbon around Limbaugh's neck.

"In just three short years, we have shattered the mentality of American Decline and we have rejected the downsizing of America's destiny. We are moving forward at a pace that was unimaginable just a short time ago, and we are never going back!" Trump said.

Trump also revived his arguments that migrants should be stopped from crossing the southern US border and that so-called "sanctuary cities" where migrants are protected are wrong.

Pelosi could be seen shaking her head as Trump spoke of his views on immigration.

After coming close to a broad conflict with Iran after he ordered the killing of Iranian military commander Qassem Soleimani, Trump said, "We are working to end America's wars in the Middle East.