'I' word hangs over State of the Union speech

America's divisions will be brought into focus as President Donald Trump delivers the annual State of the Union speech to Congress, just ahead of his expected impeachment acquittal.

The State of the Union is a grand set-piece in the US political calendar, an occasion when bitter opponents traditionally observe a truce while the president lays out a vision for the future.

But Trump will drive up Pennsylvania Avenue to the Capitol this morning (HK time) at a time of rancor arguably unmatched for decades - and likely to worsen as the November presidential election approaches.

He will be entering a chamber where only last December the Democratic-led House of Representatives impeached him for abuse of power and obstructing Congress.

"It's never safe to assume anything," a senior administration official said when asked if the impeachment will be kept out of the speech.

Trump could express regret for what even several of his own Republican senators agree was wrongful behavior in pushing Ukraine to open a questionable corruption probe against one of his main Democratic presidential opponents, Joe Biden.

Or he could entirely avoid the topic of impeachment.

Republican Senator Roy Blunt said that Trump should "avoid" the "i" word.

"It's an opportunity to move on," Blunt told The New York Times. "The other option is to address it head-on - and he is often a head-on kind of guy."

Right before the speech, the Senate will be finishing up the impeachment trial. Closing arguments took place on Monday.