Carnival Corp.'s efforts to woo passengers back to its cruise ships have hit another snag.

The world's largest cruise company canceled two of the three cruises planned for its AIDA line this month, after failing to get regulatory approval from the Italian government to set sail.

"Contrary to our expectations, the final formal approval for the start of the short trips from August 5, 2020 by our flag state Italy is still pending," Carnival said in a press release Monday. "Unfortunately, we therefore have to cancel the planned short trips with AIDAperla and AIDAmar with departure dates between August 5 and 12, 2020."

The announcement demonstrates the complicated and global regulatory landscape that Carnival and its largest competitors, Royal Caribbean Group and Norwegian Cruise Line Holdings, must navigate in order to restart cruising while the pandemic still rages. Carnival, which keeps its corporate headquarters in Miami but its place of incorporation in Panama, operates its AIDA brand out of Rostock, Germany. But the three AIDA ships that it planned to start sailing again this month are "flagged" or registered out of Italy, meaning that country has the final say on whether or not the ships can bring customers back aboard.

Carnival has not yet canceled its third planned AIDA cruise this month, which is supposed to set sail on August 16. "We assume that we will receive the last formal approval by the flag state Italy in a timely manner," the company said in its release.

But the cancellations of the first two AIDA trips do not bode well for Carnival's plans to get its ships back in operation this summer, as it fights to recover from the sweeping effects of the COVID-19 pandemic on its industry. The coronavirus effectively shut down cruising in March and has since launched dozens of lawsuits over how Carnival handled COVID-19 outbreaks on its ships early this year.

Now Carnival and its competitors are trying to convince both passengers and international government officials that it's safe to resume cruising—with limited and apparently diminishing success. Last month, the U.S. Centers for Disease Control and Prevention extended its "no sail" order for a second time, barring ships from resuming passenger operations in U.S. waters until at least September 30.

Whenever cruising does resume, it will be a much smaller industry. Carnival, which reported a $4.4 billion loss for the three months ended May 31, last week also said it was getting rid of two more cruise ships from a fleet that numbered 104 at the end of 2019. So far Carnival has announced plans to sell or scrap 15 of its ships this year, and is delaying the delivery of new ships it had previously ordered.