The Trump administration has said it is ending special protections for Salvadoran immigrants, in an action that could force nearly 200,000 to leave the US by September 2019 or face deportation.

Key points: Salvadorans have enjoyed special protection in US since earthquakes struck in 2001

Salvadorans have enjoyed special protection in US since earthquakes struck in 2001 They will have until September 9, 2019, to leave the US or adjust their legal status

They will have until September 9, 2019, to leave the US or adjust their legal status Fourth country whose citizens have lost Temporary Protected Status under Mr Trump

El Salvador is the fourth country whose citizens have lost Temporary Protected Status under President Donald Trump.

Salvadorans have been by far the largest beneficiaries of the program, which provides humanitarian relief for foreigners whose countries are hit with natural disasters or other strife.

Washington, Los Angeles, New York, Houston and other metropolitan areas are home to large numbers of Salvadorans.

They have enjoyed special protection since earthquakes struck the Central American country in 2001, and many have established deep roots in the US, starting families and businesses.

Homeland Security Secretary Kirstjen Nielsen's decision produces a serious challenge for El Salvador, a country of 6.2 million people whose economy counts on money sent by wage earners in the US.

Over the past decade, growing numbers of Salvadorans — many coming as families or unaccompanied children — have entered the United States illegally through Mexico, fleeing violence and poverty.

In September 2016, the Obama administration extended protections for 18 months, saying El Salvador suffered lingering harm from the 2001 earthquakes that killed more than 1,000 people and was temporarily unable to absorb such a large number of returning people.

Homeland Security Secretary Kirstjen Nielsen (right) determined that El Salvador had received significant recovery aid. ( AP: Andrew Harnik, file )

Ms Nielsen, who faced a Monday deadline for a decision, determined El Salvador has received significant international aid to recover from the earthquake and that homes, schools and hospitals there have been rebuilt.

Salvadorans will have until September 9, 2019, to leave the country or adjust their legal status.

"The substantial disruption of living conditions caused by the earthquake" no longer exists, the department said in a statement.

Homeland Security also said more than 39,000 Salvadorans have returned home from the US in two years, demonstrating El Salvador's capacity to absorb people.

It said the 18-month delay would give Congress time to develop a legislative change if it chooses, while also giving Salvadorans and their government time to prepare.

El Salvador President Salvador Sanchez Ceren spoke by phone on Friday with Ms Nielsen to renew his plea to extend status for 190,000 Salvadorans and allow more time for Congress to deliver a long-term fix for them to stay in the US.

AP