The match kicked off at 16:00 on the US east coast, so offices have emptied a little early.
Big screens have been erected in public viewing areas across the country, including at Chicago’s American football stadium.
An estimated 20 million Americans watched the US-Germany game last week.
This time, as many as 14 million workers could down tools to watch Tuesday’s game, costing the US economy more than $600 million in lost labor productivity, according to an estimate by Yahoo Finance.
Even President Barack Obama told reporters he had arranged his schedule around the match.
“I thought I’d get the cabinet together this morning, because we all know that America will be busy this afternoon. Go team USA,” he said.
Large viewing parties are planned across the US, including in Chicago, Kansas City and Washington DC.
At Freedom Plaza in Washington, the city government was hosting a viewing party, where viewers grabbed a spot on the stone plaza in the blistering heat hours before the match.
But not everyone will be tuning in. Despite the increased viewing figures, an NBC News poll suggests six in 10 Americans have very little interest or no interest at all in the World Cup. Only 22% had a “great deal” or “quite a bit” of interest.
Team USA’s success thus far – defeating Ghana and drawing Portugal to slip out of the group stage into the last 16 – has driven a wave of enthusiasm for football, which typically lags far behind American football, baseball, basketball and ice hockey in popularity.
The US and Belgium have not played each other in the World Cup since the first tournament in 1930, where the Americans won 3-0.
“I’m sure if we play to the best of our ability, we’ll get a positive result,” US captain Clint Dempsey said.
“For some of the guys, it’s the last opportunity, so we have to make the most of it.”
Speaking after the US lost 1-0 to Germany on Thursday, US coach Jurgen Klinsmann said: “We will work … to shift our entire game up forward. So that will put more pressure on the opponents and create more chances.”
WFuhCy6lTaQImage source: Wikimedia Commons President-elect Donald Trump celebrated his election victory at the Ultimate Fighting…
Millions of voters across the US chose to return Donald Trump to the White House…
Donald Trump declares victory in the US election as he addresses jubilant supporters in Florida.…
Stocks around the world are rising as Donald Trump appears to be on the cusp…
Donald Trump has won Pennsylvania, North Carolina and Georgia and taken a lead over Kamala…
Quincy Jones, the celebrated musician and producer who worked with Michael Jackson, Frank Sinatra, Ray…