NEW YORK >> U.S. oil field services companies Halliburton Co. and Schlumberger said they are suspending operations in Russia as the Houston, Texas-based businesses respond to U.S. sanctions over Russia’s invasion of Ukraine.

Halliburton announced Friday that it suspended future business in the country as the company complies with sanctions that prohibit transactions and work, including for certain state-owned Russian customers. Halliburton said it will prioritize safety and reliability as it winds down its remaining operations in Russia.

Haliburton said it halted all shipments of specific sanctioned parts and products to Russia several weeks ago. Halliburton said it has no active joint ventures there.

Schlumberger said Friday that it immediately suspended investment and technology deployment to its Russia operations. It said it will continue to actively monitor this “dynamic” situation.

“Safety and security are at the core of who we are as a company, and we urge a cessation of the conflict and a restoration of safety and security in the region,” Schlumberger CEO Olivier Le Peuch said in a statement.

As the war continues, and the deadly violence and humanitarian crisis worsens, companies that remain are under increasing pressure to leave.

More than 400 U.S. and other multinational firms have pulled out of Russia, either permanently or temporarily, according to Jeffrey Sonnenfeld, senior associate dean for Executive Programs at Yale University’s School of Management, who has publicized a list of corporate actions in Russia.

Oil companies ExxonMobil, Shell, and BP, along with some major tech companies like Dell and Facebook, were among the first to announce their withdrawal or suspension of operations. Many others, including McDonald’s, Starbucks and Estee Lauder, followed. Roughly 30 companies remain.

Ukrainian President Volodymyr Zelenskyy on Wednesday asked Congress to press U.S. businesses still operating in Russia to leave, saying the Russian market is “flooded with our blood.”