* Peacekeepers struggling to protect civilians in Jonglei
* South Sudan to mark two years of independence on Tuesday
* U.N. plans to deploy drones in Congo and Ivory Coast first
The United Nations should consider deploying surveillance drones and helicopter gunships in South Sudan because peacekeepers are struggling to protect civilians from violence and rights abuses, the U.N. special envoy to South Sudan said on Monday.
Hilde Johnson told the U.N. Security Council that after a U.N. civilian helicopter was shot down in December, new safety procedures and a lack of military helicopters - the peacekeepers have only three - had slowed the mission's ability to respond.
Johnson said U.N. Secretary-General Ban Ki-moon had outlined several options to boost the South Sudan mission in a report to the 15-member Security Council, including surveillance drones, helicopter gunships and more cargo and riverine transport capabilities.
"I urge the council to take urgent action to support the mission in filling these critical resource and capability gaps," Johnson told the Security Council in a video link briefing.
South Sudan will mark two years of independence from Sudan on Tuesday and Johnson said that while most parts of the country remained stable, fighting between South Sudanese troops and armed groups in the eastern state of Jonglei was of "deep concern."
Tens of thousands of people have fled their homes because of the violence and Johnson said there had been rights violations by both armed groups and national security authorities. On April 9, gunmen ambushed and killed five U.N. peacekeepers and seven civilian staff in Jonglei.
The U.N. mission has fewer than 6,900 troops to cover a country the size of France that has barely 300 km (200 miles) of paved roads. Seasonal rains have turned the region into a swamp, severing road access.
Johnson said "critical resource and capability gaps" had caused a mobility crisis for the peacekeepers that particularly affected operations in high-risk areas such as Jonglei.
"This is having a particularly detrimental effect on the mission's ability to implement its protection of civilians' mandate," she said. "Effective protection is only possible through being present in those communities most at risk."
The Security Council is due to renew the mandate of the U.N. mission in South Sudan later this month, and a senior council envoy said that peacekeepers should focus more on protecting civilians "rather than on spreading out across the country and doing infrastructure projects and nation building."
DRONES FOR CONGO, IVORY COAST FIRST
The envoy, who spoke on the condition of anonymity, said deployment of unmanned surveillance drones would be useful, but that was unlikely to happen until next year and was dependent on the success of a pilot program in Democratic Republic of Congo.
In his report, Ban also said surveillance drones should only be considered after the Congo program had been evaluated. The U.N. mission in Congo is due to begin using surveillance drones in August to monitor the thickly forested and remote eastern border with Rwanda and Uganda.
Congo has been battling a year-long insurgency by M23 rebels. U.N. experts accused Rwanda of sending troops and weapons across the border to support the M23 last year. Rwanda denies the accusation.
The United Nations has also set aside money to deploy surveillance drones eventually in Ivory Coast to monitor its border with Liberia following a recommendation by Ban and a request from the west African country.
Western Ivory Coast has been the target of deadly raids blamed on supporters of former president Laurent Gbagbo, who was ousted in a civil war in 2011 after he rejected the election victory of rival Alassane Ouattara.
While Gbagbo is in The Hague charged with crimes against humanity by the International Criminal Court, many of his top political and military allies are living in exile in neighboring West African nations.