Donald Trump has defended his hardline stance on immigration by hosting an event with relatives of people killed by what the president called “illegal alien crime” and contrasting the families who had been “permanently” separated from their loved ones with those currently languishing on the US border.

Following the massive public outcry over his administration’s “zero tolerance” approach to illegal border crossings – which has resulted in the separation of more than 2,000 children from their parents, Mr Trump reversed the policy earlier this week using an executive order. However, he was back to touting his border promises at the White House event, telling relatives: “Your loved ones have not died in vain.”

“These are the American citizens permanently separated from their loved ones,” Mr Trump said. “Permanently – they’re not separated for a day or two days, these are permanently separated”.

Although some families on the US-Mexico border have been reunited, it is still unclear how long most of the children will be away from their parents, with many already having spent far longer apart than the “one or two days” Mr Trump mentioned.

Members of 13 families participated in the White House event, which was also attended by several dozen federal immigration agents. A number of the family members joined Mr Trump onstage to share their stories and to thank the president and vice president for their support.

“Our representative is the president and the vice president. They took us in, and we’re gonna fight this battle, and we’re gonna win it,” proclaimed Ray Tranchant, a Navy veteran who said his 16-year-old daughter was killed by an undocumented immigrant in a drunk driving accident.

“I’m all about legal immigration,” he added. “But the invaders and people who come over our borders and try to take the law into their own hands … It’s evil, it hurts people, and it costs us billions of dollars a year.”

Trump's US immigration policy explained

“These are the stories that Democrats and people that are weak on immigration, they don’t want to discuss, they don’t want to hear, they don’t want to see,” Mr Trump said, having spent the last few days blaming his opposition party for the border crisis. While it is true that the wider immigration reform the president wants means going through Congress and facing Democrats – he always had the unilateral powers to not enforce the separations.

By seeking to try and blame the Democrats, Mr Trump is looking to galvanise support from his base for midterm elections that could swing the balance of power on Capitol Hill.

“Republicans should stop wasting their time on Immigration until after we elect more Senators and Congressmen/women in November. [Democrats] are just playing games, have no intention of doing anything to solves this decades old problem. We can pass great legislation after the Red Wave!” Mr Trump said on Twitter earlier on Friday.

Undocumented immigration across the US-Mexico border Show all 14 1 /14 Undocumented immigration across the US-Mexico border Undocumented immigration across the US-Mexico border Immigrant children, many of whom are separated form their parents, are housed in Texas' tent city Reuters Undocumented immigration across the US-Mexico border A two-year-old Honduran asylum seeker cries as her mother is searched and detained near the US-Mexico border Getty Undocumented immigration across the US-Mexico border Undocumented migrants ride on the top of a freight train referred to as the beast, or La Bestia Getty Undocumented immigration across the US-Mexico border A cage inside a US Customs and Border Protection detention facility in Texas Reuters Undocumented immigration across the US-Mexico border US Border Patrol Academy All new agents must complete a months-long training course at the New Mexico facility before assuming their posts at Border Patrol stations, mostly along the US-Mexico border Getty Undocumented immigration across the US-Mexico border US-Mexico border fence A group of young men walk along the Mexican side of the US-Mexico border fence in a remote area of the Sonoran Desert Getty Undocumented immigration across the US-Mexico border US-Mexico border fence in the US Man looks through US-Mexico border fence into the US in Tijuana, Mexico Getty Undocumented immigration across the US-Mexico border US-Mexico border fence US Border Patrol agent Sal De Leon stands near a section of the US-Mexico border fence while stopping on patrol on in La Joya, Texas Getty Undocumented immigration across the US-Mexico border US Border Patrol Academy US Border Patrol instructor yells at trainees after their initial arrival to the academy Getty Undocumented immigration across the US-Mexico border Memorial service in Guatemala Families attend a memorial service for two boys who were kidnapped and killed in San Juan Sacatepequez, Guatemala. Crime drives emigration from Guatemala to the United States, as families seek refuge from the danger Getty Undocumented immigration across the US-Mexico border Arrests on the border Undocumented immigrants comfort each other after being caught by Border Patrol agents near the US-Mexico border Getty Undocumented immigration across the US-Mexico border Detention holding facility A boy from Honduras watches a movie at a detention facility run by the US Border Patrol Getty Undocumented immigration across the US-Mexico border Mexican farm workers Mexican migrant workers harvest organic parsley at Grant Family Farms in Wellington, Colorado Getty Undocumented immigration across the US-Mexico border Mexican family in Arizona A Mexican immigrant family sits in the living room of their rented home in Tuscon, Arizona. The family that Arizona's new tough immigrant law had created a climate of fear in the immigrant community. Getty

“Elect more Republicans in November and we will pass the finest, fairest and most comprehensive Immigration Bills anywhere in the world,” Mr Trump added.

The “zero tolerance” policy, announced by the Justice Department in April, required agents to refer all adults caught crossing the border illegally for prosecution, including those seeking asylum. The process inevitably separates these immigrants from any children they may have brought with them.

As videos circulated online of families kept in large metal cages, and of children crying after being taken from their families, Mr Trump faced building bipartisan pressure in the last few weeks and eventually relented.

But despite reversing the separations policy, Mr Trump promised the southern border would remain “just as tough” as before, saying his executive order was “about keeping families together, while at the same time being sure that we have a very powerful, very strong border”.

Screaming children heard crying for parents at US detention centre after being separated at border under Trump policy, in distressing audio recording

Mr Trump – who has so far failed to deliver the border wall promised during his campaign – also used the “angel families” event at the White House to spotlight the Victims of Immigration Crime Engagement (Voice) Office – a group he established last year to provide resources to victims of crimes allegedly committed by undocumented immigrants, another facet of his hardline stance that played well with supporters. The office released its first quarterly report on Friday.

Multiple academic studies have shown illegal immigration does not increase crime rates. Researchers at the University of Wisconsin, Madison, for example, found that an increase in undocumented immigration since the 1990s did not increase rates of violent crime, drug and alcohol arrests, or the number of drug overdoses and DUI deaths over the same time period.

The criticism kept coming for Mr Trump’s border policy ahead of his event. In a statement issued by the United Nations Human Rights Council – which the US announced its intent to withdraw from this week – experts said that the executive order would not solve the problem, and suggesting that the separation of children from their parents “may amount to torture”.

“This executive order does not address the situation of those children who have already been pulled away from their parents. We call on the government of the US to release these children from immigration detention and to reunite them with their families based on the best interests of the child, and the rights of the child to liberty and family unity,” the group of 11 experts said.

“Detention of children is punitive, severely hampers their development, and in some cases may amount to torture,” the experts said. “Children are being used as a deterrent to irregular migration, which is unacceptable.”

Efforts to solve the problem in Congress, meanwhile, have stalled, leading to Mr Trump’s tweets that they should drop the issue. A vote on a hardline Republican immigration reform proposal failed this week, while a vote on another – a “compromise” measure meant to satisfy both more right-wing and mainstream conservatives – was pushed to next week.