U.S. Secretary of State Marco Rubio speaks with reporters [Reuters=Yonhap News]

U.S. Secretary of State Marco Rubio warned on the 21st (local time) that if Iran pushes for collecting passage fees in the Strait of Hormuz, "diplomatic agreements will become impossible."

Speaking to reporters before departing for Sweden to attend a North Atlantic Treaty Organization (NATO) foreign ministers' meeting, Rubio stated that the international community opposes Iran's collection of passage fees.

"There is currently a relevant resolution at the UN. We intend to submit it to the UN Security Council," he said. "More than 100 countries are participating in this resolution, which is the largest number in the history of the Security Council."

Regarding peace talks with Iran, Rubio mentioned that he heard Pakistan, a mediator, is scheduled to visit Iran today and expressed hope that "this will serve as an opportunity to advance the situation further."

He added, "There are some positive signs, but I don't want to be overly optimistic. Let's see what happens in the next few days."

Rubio announced that he would raise the issue of some member states refusing U.S. cooperation requests amidst the Iran war at the NATO foreign ministers' meeting.

He explained the reason for NATO's benefit to the U.S. by saying, "It provides bases that allow us to project military power in the event of an emergency in the Middle East or other regions." He continued, "This issue must be resolved, and I want to see it resolved."

Regarding Cuba, Rubio stated that "President Donald Trump prefers an agreement through peaceful negotiations," but added, "Given who we are dealing with, the likelihood of that happening is not high."

He further clarified that the recent strong measures taken against Cuba, such as strengthening sanctions and indicting former President Raul Castro, a key figure of the Cuban Revolution and its behind-the-scenes power broker, are not about "nation building." "We are dealing with issues directly related to U.S. national security," he said.

Rubio elaborated, "While Ebola is an important issue, it is an issue in Africa. Cuba is just 90 miles (about 145 kilometers) off our coast. Cuba is heading towards being a failed state, and the migration crises, violence, and instability emanating from there directly impact the United States."

Rubio noted that the Cuban government has agreed to accept the $100 million (approximately 150 billion won) in humanitarian aid proposed by the Trump administration. He stated, "We will see if they are sincere, because we do not want to see the humanitarian aid we provide fall into the hands of Cuban military enterprises, who then sell those goods at dollar stores and pocket the money."