* "Very intensive dialogue" to begin - oil minister
* Attacks cut Nigerian oil output to 20-year low
* Oil prices hit 2016 highs on lost output (Adds quote from vice-presidency statement)
By Felix Onuah and Anamesere Igboeroteonwu
ABUJA/ONITSHA, Nigeria, June 7 (Reuters) - Nigeria wants totalk to the Niger Delta Avengers militant group which hasclaimed a string of attacks that sharply cut crude output, itsoil minister said, in an attempt to stem a tide of violence inthe country's main oil-producing region.
The government has also decided that the military presencein the region, which had been increased in the last few weeks,should be scaled down, a statement issued by the vicepresident's office said.
The southern Delta swamps, where many complain of povertyand oil spills, have been hit by militant attacks on oil and gaspipelines which have brought Nigeria's oil output to a 20-yearlow, and helped push oil prices to 2016 highs on Tuesday.
President Muhammadu Buhari had appointed a team led by thenational security adviser "to begin the process of a veryintensive dialogue with those caught in the middle of this," OilMinister Emmanuel Ibe Kachikwu said late on Monday, while Buhariwas in Britain seeking medical treatment.
"I want to call on the militants to sheath their weapons andembrace dialogue with government," he said. "We are makingcontacts with everybody who is involved, the ones that we canidentify, through them, the ones that we can't identify so thatthere is a lot more inclusiveness in this dialogue."
"Probably we will suspend the operations of the military inthe region for a week or two for individuals in the creeks toconverge for the dialogue," he said.
Vice President Yemi Osinbajo, who had been expected totravel to London to meet investors on Tuesday, instead met NigerDelta state governors and military chiefs to discuss ways to endthe militancy.
A statement from Osinbajo's office said it had been decidedat the meeting that the military presence in the region shouldbe "de-escalated", although forces would be kept to providesecurity for the talks.
There was no immediate response from the Avengers groupwhich has been issuing statements through its Twitter account.
Adding to the problems of authorities trying to stem theviolence, a group in the southeast calling for secessiondeclared support for the Avengers.
"We support the Niger Delta Avengers," said Uche Madu, aspokesman for the Movement for the Actualization of theSovereign State of Biafra (Massob) which wants secession for theregion which fought a civil war from 1967-70.
A former militant group, the Movement for the Emancipationof the Niger Delta, which laid down arms in 2009 under agovernment amnesty, accused the army of a "disproportionate useof force".
MEND, which was one of the largest militant groups, alsosaid the Delta Avengers had attracted some of its formerfighters. So far it has been unclear who is behind the Avengers.
Kachikwu also said Nigeria's oil output was between 1.5million and 1.6 million barrels a day, down from 2.2 millionbarrels at the start of the year.
"Over the last two months, we have probably lost about600,000 barrels from various attacks of militants in the area,"he said. (Reporting by Felix Onuah, Ulf Laessing, Camillus Eboh and TifeOwolabi, Anamesere Igboeroteonwu and Alexis Akwagyiram; Writingby Ulf Laessing and Alexis Akwagyiram, editing by William Hardyand Adrian Croft)