Confusion and chaos reigned across the United States and the world as U.S. President Donald Trump's newly-imposed refugee ban met its first legal challenge on Saturday.

A U.S. federal judge issued an emergency stay on Saturday that bars the U.S. government from deporting some of those subject to the executive order Trump signed on Friday.

The ruling presented the first legal challenge against the executive order which slapped a 90-day ban on travel to the United States by citizens of seven Muslim-majority countries and a four-month suspension of the U.S. refugee program.

U.S. District Judge Ann Donnelly ruled that citizens of seven countries -- Iraq, Syria, Iran, Sudan, Libya, Somalia and Yemen -- who have already arrived in the United States, who are in transit and who hold valid visas cannot be removed from the United States, according to U.S. broadcaster CNN.

The executive order, widely described as a "Muslim ban," has triggered outrage and chaos across the world.

Chaotic scenes played out at U.S. airports as immigration and customs officials were struggling to grasp the new rules, with some legal residents who were in the air when the order was issued detained at airports upon arrival.

New York City's Kennedy airport "became a scene of anguish and desperation" on Saturday for the families of people detained after arriving in the United States from nations subject to Trump's travel ban, according to AP reports.

In Chicago, more than 1,000 protesters gathered at the international terminal of the O'hare airport Saturday night to protest against Trump's decision.

Chanting slogans like "Let them in" and "No hate, no fear, refugees are welcome here," protesters held signs that read "Do the right thing, let them in," "Stop profiling Muslims" and "Refugees Welcome."

Police and law enforcement members were present at the scene but were careful not to intervene. The traffic was halted to a full stop as vehicles lined up on the drive way leading to the terminal.

After the executive order took place, as many as 18 people were believed to have been detained at O'hare international airport alone, with some of them being green card holders with Muslim backgrounds, according to Chicago Tribune reports that cited lawyers working with the International Refugee Assistance Project.

In San Francisco, hundreds of protesters took to the city's international airport Saturday afternoon in response to Trump's travel ban.

As the largest airport in San Francisco Bay Area -- one of the most diversified regions in terms of ethnicity across the United States as it harbors the highest density of high-tech businesses -- SFO posted a message on its Twitter account about a roadway to the airport's international terminal being closed.

Similar events also took place at airports in Washington D.C., Denver and some other U.S. cities.

Google, Apple and others expressed dismay over the executive order as the country's tech industry relies on foreign engineers and experts for a sizeable percentage of its workforce.

Under the ban, green card holders who are legal permanent residents of the United States will not be allowed back in until they are re-screened.

Calling the travel ban "injudicious" and "discriminatory," Iran said the decision was an "open affront" to the Muslims and the Iranians.

"The decision is an open affront against the Iranian nation and the Muslim world and Iran would respond to the U.S. action in kind," Iran's Foreign Ministry said in a statement.

French Foreign Minister Jean-Marc Ayrault said Trump's decision to curb refugees flows are worrying.

At a joint press conference Saturday with his visiting German counterpart Sigmar Gabriel, Ayrault said Trump's decision to halt immigration and refugees from some Muslim-majority countries "can only worry us".

"We have international commitments that we have signed. Welcoming refugees fleeing the war, oppression is part of our duties," Ayrault added.

Canadian Prime Minister Justin Trudeau extended Canada's welcome to refugees. "To those fleeing persecution, terror and war, Canadians will welcome you, regardless of your faith," Trudeau tweeted Saturday.

source: Xinhua