Donald Trump
Donald TrumpReuters

U.S. President Donald Trump is expected to sign several executive orders on Wednesday restricting immigration from Syria and six other Middle Eastern or African countries, Reuters reported on Tuesday.

Details of the executive orders were disclosed to the news agency by several congressional aides and immigration experts briefed on the matter.

In addition to Syria, Trump's orders are expected to temporarily restrict access to the United States for most refugees, according to Reuters. Another order will block visas from being issued to Iraq, Iran, Libya, Somalia, Sudan and Yemen, said the aides and experts, who asked not to be identified.

Trump's restrictions on refugees are likely to include a multi-month ban on admissions from all countries until the State Department and the Department of Homeland Security can increase the intensity of the vetting process.

Trump is expected to sign the orders at the Washington headquarters of the Department of Homeland Security, whose responsibilities include immigration and border security.

During the election campaign, Trump caused an uproar when he called for a temporary ban on Muslim entry to the United States in order to prevent terrorism.

The call was made in the wake of the December 2015 terror attack in San Bernardino, California, in which two terrorists who had been in contact with overseas terrorist organizations killed 14 people at an office Christmas party.

Trump also promised during the campaign to institute “extreme vetting” of immigrants to protect the nation from radical Islamic terror.

“We should only admit into this country those that share our values and respect our people. We will be tough, and we will be even extreme,” Trump said in a speech in August, three months before he was elected.

Former President Barack Obama’s decision to increase the number of Syrian refugees admitted to the United States was widely criticized, due to fears that those fleeing the country's civil war would carry out attacks.

24 states announced in late 2015 they would block the program to resettle Syrian migrants within their borders due to security concerns, leading to the introduction of a Republican-sponsored bill which would curb the flow of Syrian and Iraqi refugees into the United States in order to prevent terrorists from slipping in.

The bill passed the House with broad bipartisan support but was subsequently blocked by Senate Democrats.

To block entry from the designated countries, Trump is likely to instruct the U.S. State Department to stop issuing visas to people from those nations, sources familiar with the visa process told Reuters. He could also instruct U.S. Customs and Border Protection to stop any current visa holders from those countries from entering the United States.

White House spokesman Sean Spicer said on Tuesday that the State and Homeland Security departments would work on the vetting process once Trump's nominee to head the State Department, Rex Tillerson, is installed.