For the first time in history, a Chinese destroyer has docked in a southern Iranian port, according to an Iranian state television report Sunday, the Associated Press reported.

The four-day "friendly visit," which began Saturday, will involve the two navies sharing not only expertise in the field of marine rescue but also, as some are speculating, sharing strategies on how best to maintain trade alliances between the two countries.

Taking place in the Iranian port of Bandar Abbas, the two countries will be sharing expertise in the field of marine rescue. It is a brief stop for the Chinese navy which was already on its way to the Gulf of Aden as part of an international effort to combat piracy.

According to the naval base chief in the port of Bandar Abbas, Adm. Hossein Azad, the last day of the Chinese visit will see Chinese warships staging "a joint drill in line with mutual collaboration, and exchange of marine and technical information particularly in the field of aid and rescue, reported the Associated Press.

The visit is intended to "deepen mutual understanding, and to enhance exchanges between our two countries' navies," said Chinese fleet commander Rear Adm. Huang Xinjian, according to the New York Times. "I'm sure that this visit will encourage the constant advancement of friendly cooperation between our two countries' navies."

One Iranian economist, Saeed Laylaz, said the historical Chinese naval visit indicates that "China fears that a deal over Iran's nuclear program could lead to an improvement in relations between Iran and the West," according to the New York Times.

China is already the largest buyer of Iranian oil, and pays Iran in Chinese Yuan, undercutting the U.S. petrodollar used in oil sales in much of the world. Iran then uses much of the profit to buy goods and services from China.

But to the West, and in particular the U.S., which is currently implementing international sanctions over Iran's nuclear program, growing ties and trade alliances between China and Iran only serve to complicate sanctions - and this visit is likely to generate concerns over what kind of information is being shared between the two countries.

Up until July 2013, Iran relied heavily on receiving gold payments from various countries for its oil. The U.S. then stepped up sanctions against Iran, effectively banning other countries from trading gold with Iran by using such sanctions to punish countries which did so.

This led to Iran amping up its transactions in local currencies such as Chinese Yuan and Indian rupees.