Two of the world’s biggest container shipping companies are halting cargo bookings to and from Russia. “As the stability and safety of our operations is already being directly and indirectly impacted by sanctions, new Maersk bookings to and from Russia will be temporarily suspended, with exception of foodstuffs, medical and humanitarian supplies,” shipping giant Maersk said in a statement on Tuesday. “We are deeply concerned by how the crisis keeps escalating in Ukraine,” the company added, noting that it has started “seeing the effect on global supply chain flows such as delays, detention of cargo by customs authorities across various transshipment hubs, unpredictable operational impacts.” The Denmark-based company added that it “cannot receive from or make payments to any sanctioned Russian banks, or any other sanctioned party.” MSC Mediterranean Shipping Company, a Swiss-owned container shipping line, also said it will stop all cargo bookings to and from Russia starting Tuesday. That will include “all access areas including Baltics, Black Sea and Far East Russia,” the company said in a statement. But MSC, which recently passed Maersk to become the world’s largest container shipping company, according to shipping analytics firm Alphaliner, will continue to accept and screen bookings for delivery of essential goods such as food, medical equipment and humanitarian goods. Another shipping company, CMA CGM, also suspended all bookings to and from Russia on Tuesday “in the interest of safety.” “Our utmost priorities remain to protect our employees and ensure as much as possible the continuity of your supply chain,” said the company. The halt of sailings is not required by the sanctions being placed on Russia by Western nations in response to Russia’s invasion of Ukraine last week. But it is a further sign that businesses are finding it in their own interests to cut business ties with the country, and such moves are placing additional stress on the Russian economy. These ship lines primarily sail ships that carry containers of goods, rather than bulk cargo carriers such as oil tankers or those carrying wheat and other commodities. Their refusal sail to Russian ports will put a squeeze on that nation’s ability to receive imported goods that it depends upon. The reluctance of oil tankers to call on Russia is also curtailing Russia’s sales of oil, even though the sanctions specifically allow for Russian energy exports in order to mitigate disruption to global energy markets. – CNN Business’ Chris Isidore contributed to this report