U.S. intelligence data indicates that the Russian navy received orders to mine the approaches to the ports of Odesa and Ochakiv, as well as to mine the mouth of the Dnipro River to make maritime exports from Ukraine impossible.

This was reported by The Guardian, without naming the US official from whom the information was obtained.

Russia is known to insist that exports are blocked because Ukraine has mined its ports.

"The U.S. has information that the Black Sea Fleet was ordered to block the port of Odesa and Ochakov. We can confirm that Russia, although it publicly denies mines in the northwest part of the Black Sea, is placing mines near Ochakiv. And there are also indications that they previously mined Dnipro," he commented.

The U.S. also released satellite images showing the impact of a Russian missile strike on Ukraine's second largest grain terminal near Mykolaiv on June 4.

"The images confirm that three silos and the conveyor system ensuring the loading of grain onto ships were destroyed. Because of this attack, the terminal's capacity was reduced by at least a third," the official said.