with more than 20 vessels transiting the waterway on some nights, Interior Secretary Doug Burgum said Friday.

After clearing the waters, the operation allowed for the passage of "more than 20 vessels on some nights," Burgum said on CNBC.

Given that some ultra-large tankers can hold up to 2 million barrels of crude oil, "significant volumes of oil have passed through the strait," Burgum added.

The goal of the operation is to free oil tankers and merchant ships blocked since late February, when the U.S. and Israel began military strikes on Iran.

President Donald Trump on Wednesday credited the operation with helping curb rising oil prices. In a social media post, he announced that more than 200 merchant vessels and 100 million barrels of oil had safely left the Strait of Hormuz as part of a "secret mission." Trump also told reporters that the US withdrew 22 vessels from the strait "late at night, without lights," to avoid detection.

This waterway previously handled about a fifth of the world's crude oil shipments. Its closure is blocking millions of barrels daily, triggering a global surge in oil and fuel prices.

On Friday, West Texas Intermediate crude futures traded at around $85.50 per barrel. Non-Iranian crude oil shipments through the strait have increased by approximately 50% since the beginning of the month, as the US continues to block Iranian shipments.

"I think the markets realized this before some of the tabloids did, because oil prices are starting to decline," Burgham noted.

According to data company Vortexa Ltd., at least 1.8 million barrels of oil exited the Persian Gulf in each of the first 10 days of June.