"Now that the television networks have made a decision 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.
In 2006, senators Chuck Schumer, Barack Obama, Hillary Clinton and Joe Biden voted in favour of 700 miles (1,120km) of fencing on the almost 2,000-mile border under the Secure Fence Act.
Hoping to demonstrate flexibility during his almost 10-minute speech from the White House Oval Office, Mr Trump said of the border barrier he wants built: "At the request of the Democrats it will be a steel barrier and not a concrete wall".
Migrants break through the USA border fence just beyond the east pedestrian entrance of the San Ysidro crossing in Tijuana, Mexico, on November 25, 2018.
Mr Schumer said Trump "just used the backdrop of the Oval Office to manufacture a crisis, stoke fear and divert attention from the turmoil in his administration".
In a speech that lasted roughly eight minutes, President Trump made one of his strongest cases yet for increased border protection, including the need to prevent illegal drugs, gang members and criminals from entering America unlawfully.
Mr Trump cited cases of gruesome murders of American citizens that he said had been committed by undocumented immigrants. "Division, not unity", the NY senator said.
Len Saunders, an immigration lawyer based near the border in Blaine, Wash., said those border guards - many of whom are supportive of the president's border-security efforts - may soon stop showing up for work as they begin to feel the shutdown's financial impact.
Democrats have said they support increased border security measures such as additional US border agents and technology, but have rejected the administration's claims about the security risks at the border and have raised concerns that Trump will use his speech to present a false narrative. Tomorrow the president meets with his party members at the Capitol.
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What's the reality at the border?-Mexican border, illegal crossings there have actually dropped dramatically in recent years.
He asserts that the government remains shut down because Democrats won't fund border security.
The White House suggested at the weekend that thousands of terrorists were caught attempting to cross the US-Mexico border, but in fact all but a handful were stopped at airports.
Betting site bookmaker.eu was offering odds for wagers on whether Trump would lie during his speech, declare a national emergency or end the shutdown by January 18.
The government has been partly shuttered since December 22, when Mr. Trump announced he would not sign a funding bill that did not contain wall funding.
Her fellow Republican senators, Susan Collins of ME and Cory Gardner of Colorado, issued similar appeals last week.
Such an emergency declaration would represent a dramatic escalation of the dispute and would immediately draw legal challenges.
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. But he took little action to get it built during his first two years in office.