Los Angeles has blocked airport police and firefighters from co-operating with federal immigration agents.

The latest directive is the city's most aggressive bid yet to oppose President Trump's tough crackdown and protect illegal immigrants from immigration officials.

Mayor Eric Garcetti declared it was 'un-American' to 'demonize' their neighbors simply because they are foreign, as the city beefed up its 'sanctuary city' status.

Los Angeles has blocked airport police and firefighters from co-operating with federal immigration agents in its latest bid to oppose President Trump's tough crackdown

The Los Angeles Police Department already prohibits police from asking for the legal status of a suspect even if they have probable cause.

'In Los Angeles, we don't separate people from their families because it's inhumane,' Eric Garcetti said on Tuesday.

'In Los Angeles, we don't demonize our hardworking neighbors just because they speak another language or come from another country. That's un-American.'

His words come after a wave of similar measures by cities and states to rebuff Trump's administration's immigration measures.

New York recently unveiled a set of rules for how schools must react if immigration officers turn up, the Observer reported.

New protocol instructs schools to keep Immigration and Customs Enforcement (ICE) agents out of the building unless they have a valid and urgent warrant for a pupil.

They must also get detailed information and paperwork about why they are there and promptly call attorneys from the city Department of Education.

The Los Angeles Police Department already prohibits police from asking for the legal status of a suspect even if they have probable cause

Mayor Eric Garcetti (pictured) declared it was 'un-American' to 'demonize' their neighbors simply because they are foreign as the city beefed up its 'sanctuary city' status

The rules are intended to reassure immigrant New Yorkers anxious over his enforcement agenda.

Mayor Bill de Blasio said they put the 'precautions in place' because the President's actions towards immigrants have created 'an atmosphere of particular fear and a sense that anything could happen'.

It is believed there are around 300 jurisdictions that don't co-operate with ICE to turn over illegal immigrants, Fox News reported.

President Trump has threatened to withhold federal funds from these 'sanctuary cities' - which provide haven to non-violent undocumented immigrants.

President Trump's tough immigration crackdown has left the nation divided, with some branding it 'inhumane' while others are embracing them.

It is believed there are around 300 jurisdictions that don't co-operate with ICE to turn over illegal immigrants, Fox News reported

Lawmakers in Florida, Texas, Virginia, Kansas, Kentucky, Pennsylvania, Iowa, and Wisconsin have introduced bills to penalize sanctuary cities.

Mississippi became the first state to approve the bill on Tuesday, as the governor vowed to sign it.

In California, several sheriffs are opposing proposed legislation that would prohibit police or jails from even talking to ICE.

Some sheriffs who oversee jails see the move as a breach of federal laws, Fox news reported.

LA Sheriff Jim McDonnell, who oversees the nation's largest jail, said: 'We look to be able to strike that balance between public safety and trust.

'We do a better job because we work together than we otherwise would; counter-terrorism is a great example.'

He is one of the few politicians opposing the bill because it would prohibit jail staff from identifying violent criminal aliens for deportation.

'We can allow ICE access to those individuals. That's a system that by and large works very well for us at this point and one of the main reasons I look at Senate Bill 54 as something that is unnecessary.'

McDonnell also told the Los Angeles Times that the legislation would hurt immigrants – not help them.

New York is similarly opposed to Trump's policies and most recently unveiled a set of rules for how schools must react if immigration officers turn up, the Observer reported.

He said if immigration officials cannot pick up illegal immigrants from jails, then they will be forced to look for them in communities.

'They are going to have no choice but to go into the communities and arrest not only the individual they are seeking but also people who are with that person, or other people in the area who are undocumented,' McDonnell said. 'That is something none of us want.

President Trump undertook one of his biggest campaign promises during his first week in office when he signed an executive order that vastly overhauled current immigration law.

Under the new policies, deportation restrictions were stripped to the bare minimum, meaning that up to 8million people could be considered priorities for deportation, according to a study done by the Los Angeles Times.

These new policies have opened the doors for roundups and detentions of illegal immigrants on a scaled that has not been seen in roughly 10 years.

The Times' calculations were based on interviews with experts who studied the order, as well as two internal documents that signal how seriously immigration officials are taking Trump's directive.

These expansive deportations could have significant consequences on the United States population.

Lawmakers in Florida, Texas, Virginia, Kansas, Kentucky, Pennsylvania, Iowa, and Wisconsin have introduced bills to penalize sanctuary cities

Families could be separated, businesses catering to immigrant customers could be shuttered, and crops could be left to rot, unpicked, due to labor shortages in industries that rely on an immigrant workforce such as agriculture, reported the Times.

New policies and instructions will significantly expand President Obama's focus on deporting only recent arrivals, repeat violators and people with criminal violations.

Only about 1.4million people were considered priorities for removal under the past administration.

'They really are going to round up everybody they can get their hands on,' according to David Leopold, a former president of the American Immigration Lawyers Association.

Trump's orders tell immigration officials to deport all immigrants convicted of crimes, and also all those that have not been charged but are believed to have committed crimes.

That number applies to the 6million people who are believed to entered the United States without passing an official border crossing, according to the Times.

It comes as several city officials and sheriffs around the U.S. lashed out Tuesday at a White House report aiming to shame them over what the Trump administration sees as lax immigration policies, saying it includes wrong or misleading information about recent arrests of immigrants or their jail policies.

The pushback was not just from liberal local governments that are at odds with President Donald Trump over immigration crackdowns and his promise to deport 'bad dudes' living in the United States illegally. In Texas, the elected Republican sheriff of conservative Williamson County said his jail didn't refuse four recent immigration detainer requests as claimed.

The list was prompted by an executive order signed by Trump in January that called on the government to document which local jurisdictions aren't cooperating with federal efforts to find and deport immigrants in the country illegally.

The first list was released Monday, citing 206 examples of immigrants who were said to have been released from custody by local jails despite requests from federal agents. The requests, often called 'detainers,' have taken on a greater role in the immigration debate under Trump, who strenuously opposes local policies that grant leniency to people in the country illegally.

Many 'sanctuary cities' choose to not honor the requests when immigrants complete their sentences and are released from jail.