U.S. Secretary of State Antony Blinken is expected to announce Tuesday an aid package to help Ukraine deal with damage to its electrical system caused by Russian attacks.

The announcement comes on the sidelines of a meeting of NATO foreign ministers in Romania.

Senior U.S. officials told reporters the aid will be “substantial,” but did not detail the exact size and nature of the package.

The United States is also expected to call on other Ukrainian allies to do more to help Ukraine avert power cuts as colder weather sets in.

Some information for this report came from Agence France-Presse and Reuters.