Washington: The trial of US President Donald Trump's former campaign chairman, Paul Manafort, is set to begin with tales of lavish spending, secret companies and millions of dollars of Ukrainian money flowing to his pocket from offshore bank accounts.

But what is expected to be missing from the trial, which begins on Tuesday (US time), will be answers about whether the Trump campaign coordinated with the Kremlin during the 2016 presidential election or any mention of Russia at all.

Manafort's trial, the first arising from special counsel Robert Mueller's investigation, centres on his Ukrainian consulting work and will only briefly touch on his involvement with the president's campaign.

But the broader implications are unmistakable.