U.S. politicians from New York to California are calling for public pensions to shed hundreds of millions of dollars in investments tied to Russia. So far, the retirement funds aren’t moving quickly to divest. In many cases, they can’t.

The funds have relatively small exposure, but unwinding such assets is complex and could mean losses as they are trading at deep discounts and liquidity is scarce. Many of the largest retirement systems, which invest billions for teachers and other public servants, are adopting a patient approach.

But less than 1% of its $473.6 billion portfolio is in Russian-linked assets. It includes mostly stocks or index funds, as well as real-estate investments and private equity, worth in total about $900 million to $1.1 billion. The system isn’t taking precipitous action. Instead, it’s merely “monitoring current events and will take action as appropriate to protect the interests of our members,” Frost said.

Read more: BNN Bloomberg