US President Donald Trump is set to argue that an immigration “crisis” requires his long-promised wall along the Mexican border.
Mr Trump will make his case in his first speech from the Oval Office at 21:00EST (0200 GMT Wednesday), ahead of a trip to the border on Thursday.
A partial government shutdown has been in effect for 17 days after lawmakers failed to break a budget impasse.
The president is insisting that $5bn (£4bn) be included for the border wall.
The decision by the major US TV networks to set aside at least eight minutes of airtime for the speech has sparked controversy and fuelled debate on social media.
Critics pointed out that the networks aired President George W. Bush’s prime-time address on immigration in 2006, but did not air one by President Barack Obama in 2014.
Democratic leaders in the House and Senate released a joint statement saying the speech would be misleading and demanding airtime to counter Mr Trump’s arguments.
“Now that the television networks have decided to air the President’s address, which if his past statements are any indication will be full of malice and misinformation, Democrats must immediately be given equal airtime,” their statement read.
The partial government shutdown, which began on 22 December, has affected 25% of the government. Some 800,000 federal employees have been temporarily laid off – or forced to work without pay.
While its repercussions ripple across the country, Mr Trump has also threatened to bypass Congress and invoke emergency powers to build the wall along half the 2,000-mile (3,100km) border.
White House press secretary Sarah Huckabee Sanders said in a tweet that Mr Trump would use his visit to the border on Thursday to “meet with those on the front lines of the national security and humanitarian crisis”.
Curbing illegal immigration was one of the main campaign promises Mr Trump made when he ran for president.
During the campaign for the midterm elections in November, he repeatedly agitated over a caravan of Central American migrants making its way towards the US border with Mexico.
Mr Trump deployed about 5,800 troops to the border and described the migrants as an “invasion”.