Sources briefed on the matter said third-party agents had made contact with the hostage-takers, who have not been publicly identified, and talks to free the men are under way.
The U.S. government is not considering any type of military operation to rescue the seamen, officials said.
The kidnapped men, employees of the maritime transportation company, Edison Chouest Offshore, have only been identified as the captain and chief engineer of the C-Retriever, an oil supply vessel. The U.S. government itself has a longstanding policy against complying with ransom demands, but private companies are not subject to such a policy.
The FBI is assisting in the matter but is not negotiating directly with the kidnappers, sources said.
Spokesmen for the FBI have declined repeated requests for comment, saying they do not want to jeopardise the safety of the captives.
The C-Retriever was attacked in the wee hours of October 23 by an unknown number of armed assailants who then separated the crew by nationality and made off with the Americans, a Pentagon official told ABC News the day of the attack.
In the days since, a proof-of-life call was made and the U.S. government has verified that the two Americans are being held on land as their fate is negotiated.
While globally piracy was down last year to its lowest levels in seven years, cases in Nigeria are on the rise.
According to the International Maritime Bureau, pirate attacks off Nigeria’s coast have jumped by a third this year — allegedly perpetrated by criminal gangs who are looking for cargo ships with commodities, and seeking ransom for hostages. Around the world there have already been more than 200 “incidents” involving piracy this year, including 11 hijackings, the IMB said.
Information from This Day was used in this report.