US President Donald Trump speaks to various world leaders amid immigration executive order

US President Donald Trump spoke by phone on Saturday with various world leaders, amid growing international alarm and a legal challenge over his moves to drastically limit Muslim immigration to the United States.

In a flurry of calls that started early in the morning and rounded out an already frantically paced week, Trump spoke with Japanese Prime Minister Shinzo Abe, German Chancellor Angela Merkel and Russian President Vladimir Putin.

He has calls planned for later in the day with French President Francois Hollande and Australian Prime Minister Malcolm Turnbull.

The conversations gave the US president an early opportunity to explain new policies that have baffled and unnerved much of the rest of the world—particularly his order to temporarily halt all refugee arrivals and those of travellers from seven mainly Muslim countries including war-wracked Syria.

The calls also allow him to start developing ties with countries that have been close allies with the United States in recent history, as well as Russia—a perennial foe, but a country with which Trump has said he is keen to improve relations.

Trump’s pronouncement on Muslim immigration makes good on one of his most controversial campaign promises to subject travellers from Islamic countries to “extreme vetting,” which he declared would make America safe from “radical Islamic terrorists.”

“This is big stuff,” the new US president declared at the Pentagon yesterday, after signing an executive order entitled “Protection of the nation from foreign terrorist entry into the United States.”

The decree suspends the entire US refugee resettlement program for at least 120 days while tough vetting rules are established.

The new protocols “ensure that those approved for refugee admission do not pose a threat to the security and welfare of the United States.”

In addition, they specifically bar Syrian refugees from the United States indefinitely, or until the president himself decides that they no longer pose a threat.