President Donald Trump and Israeli Prime Minister Bibi Netanyahu reached an understanding during a White House meeting Wednesday that Washington will take steps aimed at cutting back Iran’s oil exports to China, according to a report by Axios citing two U.S. officials familiar with the discussions.

“We agreed that we will go full force with maximum pressure against Iran, for example, regarding Iranian oil sales to China,” Axios reports, quoting a senior U.S. official.

China purchases the vast majority of Iran’s crude oil—more than 80 percent of its total exports—making Beijing the primary source of Tehran’s oil revenue. Any significant disruption to that flow would sharply reduce the income Iran derives from its energy sector.

The renewed focus on oil sanctions comes as diplomatic contacts between Washington and Tehran quietly resumed.