The Trump administration on Wednesday imposed new sanctions on the government of Syrian President Bashar al-Assad, designed to prevent private and foreign investors from supporting reconstruction and revenue-producing efforts in the war-torn country.

The measures were the first implementation of the Caesar Act, passed by Congress last year and named for a pseudonymous photographer who smuggled out thousands of pictures of torture in Assad’s prisons.

Together, the Treasury and State departments targeted 39 individuals and entities for new economic and visa restrictions. Many of the measures match or expand sanctions previously enacted by the administration and European allies.

“The United States will not stand by while the Assad regime displaces civilians to benefit regime-friendly elites,” Treasury Secretary Steven Mnuchin said in a statement. “The Treasury Department will continue to use its tools and authorities to target the Assad regime and its supporters, as they seek to profit off the suffering of the Syrian people.”

Many of the Treasury sanctions target private-sector investment in hotel and mall developments, many of them planned on land abandoned by those arrested or fleeing the violence.

Secretary of State Mike Pompeo announced that Assad and his wife will be placed under sanctions. This is the first time the United States has taken the step for Asma al-Assad, whom the European Union placed under sanctions in 2012.

Pompeo called Asma al-Assad “one of Syria’s most notorious war profiteers.” A senior administration official, one of several who were authorized to brief reporters on the condition of anonymity, said she was involved in “various holding companies” and other activities as “the business head of the family.”

The designations also extend to Maher al-Assad, the president’s brother and head of the infamous Fourth Division of the Syrian Arab Army, and Bushra al-Assad, the president’s sister, who resides abroad, as well as other members of the Assad family and the prominent Hamsho family, which has close ties to the government.

“As of today, the sanctions provisions of the Caesar Act are fully in effect,” Pompeo said in his statement. “Anyone doing business with the Assad regime, no matter where in the world they are, is potentially exposed to travel restrictions and financial sanctions.”

Although Assad and his Russian and Iranian allies have retaken much of the territory initially occupied by opposition forces during the nine-year civil war, it has come at the cost of the destruction of much of the country. The United States and Europe have said they will not contribute to Syria’s reconstruction until Assad leaves office.

“We intend to have a severe chilling effect on any outside investors who would be contemplating doing business with the Assad regime in areas of construction and other sectors which would enable” Assad “to generate revenue and funds that it uses to pay for its war against the Syrian people and to fund the machine of the Assad regime that has been carrying out mass atrocities since the beginning of the Syrian conflict,” a second administration briefer said.

House Foreign Affairs Committee Chairman Eliot L. Engel (D-N.Y.) called the implementation of the Caesar Act “a welcome but overdue step. . . . It shouldn’t have taken so long to get this bill enacted, and it shouldn’t have taken Congress to push the administration to take a positive step to address the crisis.”

Syrian state media, quoting an unnamed foreign ministry official, said the new measures “surpassed all international laws and traditions” and reflected “the behavior of gangs and bandits.”

Apparently referring to current upheaval in the United States over racially charged police actions, it quoted the official as questioning American standing to criticize the human rights behavior of others, saying that the administration “chases down its citizens in the streets” and “practices the ugliest forms of racism by copying the crimes of its founders against natives.”

The Caesar Act is specifically intended to promote accountability for the death or imprisonment and torture of hundreds of thousands of Syrian civilians, and requires the administration to ensure its actions do not impede humanitarian assistance.

Years of sanctions have had little apparent effect on Assad’s hold on power.

But administration officials cited rising prices and scarcities, as well as rising street demonstrations in Syria. A statement Wednesday from the Syrian Central Bank also blamed new “unilateral coercive economic measures” under the act for an official devaluation of the Syrian pound, cutting its value nearly in half, after it had fallen sharply for weeks on the black market.

Dadouch reported from Beirut.