US Vice President Joe Biden begins an official visit to Panama Monday for meetings on the expansion of the canal, which could have major impact on US ports.

During his visit, Biden will also meet Panamanian President Ricardo Martinelli to discuss in part Panama's request the United States withdraw the chemical weapons it has stationed there since World War II.

The $5.6 billion canal expansion, expected to be completed by 2015, will permit the passage of so-called "super-cargo" ships, which can carry up to 12,000 containers. Currently, the largest ships that can navigate the canal can carry up to 5,000 containers.

Allowing passage of these mega freighters will directly impact traffic at major US ports, including Baltimore, Maryland, Charleston, South Carolina, and Savannah, Georgia.

For this reason, Biden will be accompanied by top US port officials and Transport Secretary Anthony Foxx.

"Super-cargo" ships represent about 30 percent of the current world fleet, according to US sources.

Biden is also set to discuss the sensitive issue of chemical weapons, stationed on the island of San Jose.

Last month a senior Panamanian foreign ministry official told AFP the process of withdrawing the weapons will be completed by 2014. He says the arsenal includes six unexploded bombs that once may have had mustard or phosgene gas.

A senior White House official said the US is committed to resolving the issue in a timely manner.