American Express (AXP) is joining a growing list of large multinational companies severing ties with Russia amid its invasion of Ukraine.

"Since the beginning of this crisis, we have been complying with U.S. and international sanctions, which has resulted in us halting relationships with impacted bank partners in Russia, and we will continue to comply with all relevant laws as the situation evolves," said American Express Chairman and CEO Stephen Squeri in a memo to employees obtained by Yahoo Finance.

Western allies moved to block "selected" Russian banks from the SWIFT payment system this past weekend. The decision essentially denies Russia access to financial markets globally and opens its economy up to a potentially severe decline.

In light of the sanctions multinational companies such as Mastercard, Visa and BlackRock have sought to distance themselves from doing business in Russia.

Here is the full memo from American Express Chairman and CEO Stephen Squeri:

"Like many of you, I am shocked and saddened by the crisis unfolding in Ukraine, and recognize that some of our colleagues, customers, their families and loved ones, have been affected by the devastating human suffering we have been witnessing. I want to share what we are doing as a company in response to this crisis.

As always, our priority is the safety and wellbeing of our colleagues. While American Express does not employ anyone directly in Ukraine, we do have hundreds of colleagues in the surrounding countries. We also have a small number of colleagues in Russia. To date our colleagues in all these areas have been confirmed safe, for which we are incredibly grateful, and we will continue to do our best to support them.

When it comes to our customers and our business, the situation continues to evolve rapidly. Our business in Russia is small, consisting of one partner that issues cards and a handful that acquire merchants for payment transactions. Since the beginning of this crisis, we have been complying with U.S. and international sanctions, which has resulted in us halting relationships with impacted bank partners in Russia, and we will continue to comply with all relevant laws as the situation evolves.

Throughout history and in terrible times we’ve always done the best to support our customers, and this situation is no different. Some of our customers are providing critical humanitarian aid in the region and risking their lives to report on this crisis, and we will continue to do all that we can to back them.

Cyber security is another key area of focus for us. American Express is taking all necessary steps to detect, prevent, and respond to any malicious activity through our layered defenses. We remain vigilant and will continue to monitor this situation for any threats posed to American Express.