The United States says it will work to help address grievances of people in Nigeria's oil-rich Niger Delta region, if militants end their campaign of kidnappings and sabotage.
The United States is renewing its appeal for the release of three hostages, two American and one British, now entering their second month in captivity.
They were among nine foreign oil workers kidnapped on February 18, while working on a Nigerian pipeline for Shell Oil. Six have been released.
The militant group, calling itself the Movement for the Emancipation of the Niger Delta, has a list of demands, including more local control over the region's oil wealth, the release of two jailed ethnic Ijaw leaders and compensation for oil pollution of delta villages.
Some 20 million people live in poverty alongside the multi-billion dollar oil industry in Nigeria.
The U.S. ambassador in Nigeria, John Campbell, says the United States would be willing to play a more active role in tackling the grievances of the delta people, if armed groups in the area renounce hostage taking.
"Let me reiterate that, while we have sympathy for the legitimate aspirations for development of the people in the delta, and we already are, and will continue in the future, to be involved in assistance programs there, hostage-taking never, ever is justified," Campbell says. "I will hope that, once we emerge from the current hostage crises, once those that are held hostage are released, assuming that no further hostages are taken, that we will be able to accelerate our assistance in that region."
Hostage-taking and pipeline sabotage have been the main tactics by militants. The latest attack came Saturday, when the Italian oil company, Agip, says one of its pipelines was blown up.
Abuja-based lawyer and observer Maxi Okwu says he thinks there must be some political concessions before the violence will ease.
"Our economy will obviously be adversely affected," Okwu says. "The national political situation is getting tense, and apparently those young men down there have tasted blood and are moving for the kill. They are more confident, and it appears as if the president has no answer - and, as a matter of fact, what I'm seeing, negotiating with them has given them a lot of courage to make serious demands, and the government has no answer. So, it is a most dangerous situation, and I think that it must be resolved politically."
President Olesegun Obasanjo has ruled out the use of force to free the remaining hostages.
But the situation is taking an economic toll.
Royal Dutch Shell has evacuated its staff from the worst affected areas. And, in the wake of the violence, oil production overall has dropped by more than 500,000 barrels per day. This represents about a quarter of Nigeria's total oil production.