Having been denied permission by Burma's ruling military government to drop off aid for cyclone victims, U.S. warships are being pulled out of the area.

The U.S. military ordered its ships loaded with relief aid for Burma's cyclone victims to leave the area Thursday after the country's junta refused to give them permission to help survivors. (U.S. Navy, Chief Petty Office Ty Swartz/Associated Press)

In a new release, the United States' top military commander in the Pacific, Adm. Timothy Keating, said the USS Essex and its accompanying vessels could return if permission is granted.

But after 15 unsuccessful attempts to persuade the Burmese government to permit ships, helicopters and landing craft to unload aid, the U.S. navy has given up for now.

"I am both saddened and frustrated to know that we have been in a position to help ease the suffering of hundreds of thousands of people and help mitigate further loss of life, but have been unable to do so because of the unrelenting position of the Burma military junta," Keating said.

The American ships are scheduled to leave Thursday.

Burma's refusal to let U.S. military in comes after years of strained relations between the two countries.

Burmese state media has said assistance from U.S. warships "comes with strings attached" that are "not acceptable to the people of Myanmar," citing fears that Washington wants to overthrow the Burmese junta. In the past, the U.S. has imposed a variety of economic and trade sanctions on Burma, also known as Myanmar, in protest against the policies of the country's military junta government.

Burmese children stand inside their home which was damaged by Cyclone Nargis, on the outskirts of Rangoon. (Associated Press)

Aid officials had been hoping that the regime would clear the way for foreign naval vessels to begin landing supplies directly to survivors in the Irrawaddy River Delta, one of the areas worst hit by the cyclone and largely inaccessible by road. Getting into the swampy delta region has been one of the biggest barriers to delivering aid since Cyclone Nargis struck on May 3.

On Monday, one month later, international aid experts said the country's reclusive military regime was still restricting access to those worst-hit areas. At least 78,000 people are dead and 56,000 missing, while more than 2.4 million were left homeless.

The most recent UN assessment of the situation, released Tuesday, said aid groups are still unable to deliver food and clean water to the 1.1 million survivors, who are at risk of malnutrition and disease. Some aid officials have expressed shock that many of the survivors have not even received basic aid four weeks after the storm hit.

Of the 1.3 million people who are getting help in Burma, also known as Myanmar, most have been "reached with inconsistent levels of assistance," the UN said.

"There remains a serious lack of sufficient and sustained humanitarian assistance for the affected populations," the report said.

With files from the Associated Press