Melania Trump makes second migrant children visit, in Arizona

US First Lady Melania Trump was on Thursday greeted by protesters in Phoenix as she made a second visit to meet undocumented child migrants while her husband's administration battles to contain a border crisis.

The trip to Arizona came a week after her visit to Texas was overshadowed by her choice of a controversial jacket, fanning outrage over forcible separations of migrant children from their parents.

President Donald Trump was last week forced into a U-turn on the separations, but about 2,000 children remain split from their parents.

On Thursday, the first lady toured a short-term detention facility in Tucson where she met children as young as five at a centre housing migrants from Guatemala or Honduras, all of whom had been there less than 72 hours.

In Phoenix, her motorcade swept past a protest of several dozen and a large, inflatable depiction of the president in a Ku Klux Klan robe. "End All Cages. Free the Parents and Children," read one sign.

There she visited a centre currently housing 121 children, including 33 aged five or under and four babies with their mothers.

As the press pool was leaving, she could be heard talking about the experience of children separated from their parents: "It's hard to understand where are their parents because of their age."

One day earlier, a "compromise" bill designed to put a definitive end to family separations failed in Congress, embarrassing the president.

It was opposed by all Democrats but also by conservatives who argued it did not do enough against illegal immigrants.

The policy of forcible separations saw the first lady make a rare foray into politics, saying she hated to see families separated and calling for bipartisan immigration reform to fix the issue.

"I want to thank you for all your hard work," she told officials on her first stop at a Customs and Border Patrol facility in Tucson.

Five-year-olds

"I know how difficult and dangerous your daily jobs are," the first lady added. "I am here to support you and help any way I can."

A week after being castigated for wearing a jacket emblazoned with the words "I really don't care. Do u? the 48-year-old mother of one and former model, herself an immigrant from Slovenia, played safe in white pants and a black top.

"Hola! Hola! Hello! How are you? Como estas?" the first lady said in Tucson, greeting the children. They responded by saying, "bien." She asked them about their ages. "Who is five?" she asked. Six hands shot up in the air.

Trump held up five fingers and asked one little girl, "Are you five?" The girl then gave the first lady a high five, and the pair fist-bumped.

She also asked who liked football. When several said they did, she smiled back saying: "Me, too."

Earlier, she held a roundtable discussion with Border Patrol, Immigration and Customs Enforcement, the US Marshals Service and a local rancher.

Her spokeswoman said the first lady wanted to "learn" from those on the ground. "She's advocating for quality care for these children under difficult circumstances," Stephanie Grisham told reporters.

Border Protection Commissioner Kevin McAleenan said 1,600 people, including 539 in families, tried to enter the United States illegally the day before.

Chief patrol agent Rodolfo Karisch showed Trump a photo of a six-year-old boy crossing the desert with a coke bottle and a note. "People also have to understand the danger of the desert, of the heat," he said.

On June 21, she was castigated for boarding her aircraft en route to meet children at the US-Mexico border in Texas in the $39 Zara jacket.

Once in Texas, Trump asked how she could "help these children to reunite with their families as quickly as possible."