Some migrant children have been detained in so-called tent cities, without their parents, as part of the Trump administration's "zero tolerance" border policy.

Housing a child in these locations costs $775 per child per night on average, according to NBC.

Business Insider research showed Trump hotels in New York, Las Vegas, and Washington, DC, all offering rates for suites lower than $775.

The migrant children being detained away from their parents in tent cities could be put up in a suite at one of President Donald Trump's hotels at a rate lower than what the US government is reportedly spending on them.

According to NBC News, it costs the Department of Health and Human Services $775 per person per night on average to house detained children in the temporary shelters near the US border.

Business Insider found several suites at Trump hotels advertising rates lower than that, including a junior suite in the Trump International Hotel in Washington, DC, offered at $757 before taxes and fees for the night of June 23 ($869.04 including taxes and fees).

A night in a junior suite is on offer for $757 excluding taxes and fees. Trump Hotels

At the New York City Trump International Hotel & Tower, just off Columbus Circle near Central Park, a one-bedroom suite with a city view was available for $710 before taxes and fees July 3. Trump's Las Vegas hotel was offering a penthouse suite with a view of the strip at a rate of $710 on July 3.

The Washington junior suites have a king-size bed with Trump-branded linen, a separate seating area with a 55-inch flat-screen TV, an "executive desk," and a chandelier. The bathrooms have two tubs, one of which is lined with marble, and come with high-end toiletries.

Photographs from one of the three tent cities, near Tornillo, Texas, show tent dormitories filled with bunk beds and a mobile medical unit based out of a truck.

Here is where the children sleep:

The tent cities have been created in response to a surge in migrant children in custody. Trump's "zero tolerance" immigration policy saw more than 2,000 children separated from their parents in the policy's first six weeks, according to official figures.

The policy dictates that all adults who are detained at the border on immigration offenses be charged criminally, requiring them to be separated from any children they traveled with.

This photograph shows what appears to be a row of portable toilets in the bottom-right.

Migrant children are being held in a tent city in Texas near the US-Mexico border. Reuters/Mike Blake

Officials told NBC News the accommodations cost so much because of extra expenses for security, air conditioning, medical workers, and other government contractors, all brought in at short notice.

It would cost less to keep children with their parents, according to NBC News. Housing children with their parents in detention centers like the US Customs and Immigration Enforcement center in Dilley, Texas, costs $298 per person per night.

Housing a person in a permanent facility, such as the Casa Padre center in Brownsville, Texas, costs $256 per person per night.

Backlash against the administration's policy has surged as photographs and audio footage of detention centers reached the public domain. Hundreds protested outside the Tornillo tent city on Sunday, calling for a change to Trump's immigration policies and the separation of families.