US President Donald Trump has made his first TV address to the nation from the Oval Office, escalating a stand-off with Congress that has led to an 18-day partial government shutdown.
Mr Trump insisted on funding for his long-promised border wall with Mexico.
However, he did not declare an emergency that would enable him to bypass the lower house of Congress now controlled by the opposition Democrats.
Democratic leaders accused him of holding the American people hostage.
The Republican president wants $5.7bn (£4.5bn) to build a steel barrier, which would deliver on his signature campaign pledge.
But Democrats – who recently took control of the House of Representatives – are adamantly opposed to giving him the funds.
The ongoing closure of a quarter of federal agencies is the second-longest in history, leaving hundreds of thousands of government workers unpaid.
What did Trump say?
In an eight-minute live address on Tuesday night, he blamed the Democrats for the government shutdown.
The situation at the border was, he said, a “humanitarian crisis, a crisis of the heart and a crisis of the soul”.
Mexico, he said, would pay for the wall through a revamp of the North American Free Trade Agreement, which is yet to be ratified. Economists have disputed this. Mexico has never agreed to pay for the wall.
The president also said that 90% of heroin sold in the US comes from Mexico, though US government figures make clear all but a small percentage is smuggled through legal points of entry.
Mr Trump correctly pointed out that Democrats including Mr Schumer had voted for a physical barrier to cover 700 miles (1,120km) in 2006.
Mr Trump also cited cases of American citizens “savagely murdered in cold blood” by undocumented immigrants.
On Thursday, he is due to visit the actual border.
How did Democrats respond?
House Speaker Nancy Pelosi and Senate minority leader Chuck Schumer demanded that Mr Trump end the shutdown.
“The fact is the women and children at the border are not a security threat, they are a humanitarian challenge,” said Mrs Pelosi.
She accused President Trump of “holding the American people hostage” and “manufacturing a crisis”.
Mr Schumer accused Mr Trump of trying to “govern by temper tantrum” and appealing to “fear, not facts”.
Democrats argue that maintaining existing border fencing, using high-tech tools to scan vehicles at ports of entry and hiring more personnel would be cheaper and more effective than a wall.
Playing for time
There were two audiences for Donald Trump’s address to the nation on Tuesday night. The first was the American public, who polls indicate are generally uninterested in his border wall proposal, viewing the president as responsible for the government shutdown. The other was Republicans in Congress, who Mr Trump needs to keep in the fold if he is going to get anything out of this extended political confrontation.
It seems unlikely that the president said anything that will move the needle with the public at large. The arguments were familiar – and some have already been debunked. The president has been saying there’s a “crisis” at the border practically since he first started campaigning for the job.
As for congressional Republicans, the speech was a demonstration that Mr Trump is going to use every arrow in his presidential quiver to get his wall.
The president may have bought himself a bit more time for negotiations. It’s just not clear what good it will do him.
What’s the reality at the border?
The border is 1,954 miles long, with about 650 miles of various types of fencing already in place through California, Arizona, New Mexico and Texas.
Mr Trump says much of the wall has already been fully renovated or built. Border authorities say work has begun on building improved security infrastructure, and money made available has largely been tied to existing barrier designs.
Illegal border crossings fell from 1.6 million in 2000 to fewer than 400,000 last year, and research indicates that undocumented immigrants are much less likely to commit crime than native-born American citizens.
On Friday, White House press secretary Sarah Sanders said nearly 4,000 known or suspected terrorists had been caught attempting to enter America illegally, and referred to the Mexican border as the “most vulnerable point of entry”.
White House adviser Kellyanne Conway said later that Ms Sanders had been referring to US government figures for 2017, when 3,775 known or suspected terrorists were prevented from entering America.
A clarification by the US department for homeland security states that most of these interceptions occurred at airports while adding, “The number of terror-watchlisted individuals encountered at our Southern Border has increased over the last two years. The exact number is sensitive…”
Only six immigrants on a federal watch list were stopped on the southern border in the first half of 2018.
How much support does Trump have?
He is backed by most of his party, although a handful of moderate Republican senators have called for an end to the shutdown before the border wall issue is resolved.
The sole Republican among the nine Congress members who represent southern border districts is, like his Democratic colleagues, opposed to Mr Trump’s wall plan, CBS News reports.
A new opinion poll suggests just over half of Americans (51%) blame President Trump for the government shutdown.
However, 77% of Republicans say they support his refusal to approve a budget without taxpayer dollars for the US-Mexico border wall, according to the Reuters/Ipsos poll.
What would an emergency declaration achieve?
In theory, it would allow the president to bypass the usual political process, and access military spending to fund his barrier.
Analysts say such a declaration may still follow.
But the president would be accused of usurping Congress’s constitutional power of the purse, and the move would be bogged down in a quagmire of legal challenges.