The administration of US President Donald Trump has threatened to cut off arms supplies to Ukraine if Kyiv continues to attack Russian oil refineries, sources among European officials told the Financial Times, the latter reports.

In particular, Washington representatives have threatened to suspend the operation of the Prioritized Ukraine Requirements List (PURL) mechanism—through which European countries purchase American weapons for the Ukrainian army—as well as to refuse to share intelligence.

According to sources, such threats were made during telephone conversations over the past weekend.

The White House, however, has declined to officially confirm these calls and comment on the information about the threats.

Trump wants Ukraine to stop attacking Russian oil refineries because he believes these attacks are driving up automobile fuel prices in the US.