The leaders spoke for the first time since the announcement in a 30-minute call and agreed to discuss the issue further at the G7 summit in Canada later this week.
"What I can say with full confidence, though, is that prices will rise—for producers and consumers alike—which is good for gold but a headwind for continued economic growth."
The Black Lung Disability Trust Fund is at risk of insolvency due to soaring debt and a slashing of coal-company contributions through a scheduled tax cut.