* UK willing to talk, but not about "sovereignty"
* Britain, Argentina fought 1982 war over Falklands
* UK envoy doesn't comment on nuclear arms charges
By Louis Charbonneau
UNITED NATIONS, Feb 10 (Reuters) - London's U.N. ambassador warned Argentina on Friday that Britain would "robustly" defend the Falkland Islands if necessary, but added that his country remained open to bilateral talks with Buenos Aires on any issue except the islands' sovereignty.
British Ambassador Mark Lyall Grant was speaking to reporters after Argentine Foreign Minister Hector Timerman met with U.N. Secretary-General Ban Ki-moon and the president of the U.N. Security Council to ask for help in stopping what he said was Britain's "militarization of the South Atlantic."
"We are not looking to increase the war of words, but clearly if there is an attempt to take advantage of the 30th anniversary of the Falklands war by Argentina, then we will obviously defend our position and defend it robustly," Lyall Grant said.
The British envoy's comments came a day after British Prime Minister David Cameron vowed to defend the islands "properly."
Britain and Argentina fought a 10-week war over the Falkland Islands in 1982 after Argentina invaded the South Atlantic islands, which the Argentines call Las Malvinas. London has refused to start talks on sovereignty with Buenos Aires unless the 3,000 islanders want them.
Tensions have risen before the 30th anniversary of the Falklands conflict this year. Oil exploration by British companies off the islands has raised the stakes.
Timerman repeated accusations that surfaced in the British press about a nuclear submarine being sent to the South Atlantic. He said that bringing atomic weapons into the region violated Latin America's treaty banning the presence, pursuit or use of nuclear weapons.
Britain has signed two protocols to the 1967 treaty, according to which it vowed to support the maintenance of a nuclear-weapons-free zone across Latin America.
Lyall Grant denied militarizing the region and said Britain had a "purely defensive military posture" for the islands. He neither confirmed nor denied reports a nuclear-armed British submarine is lurking around the Falklands.
"We do not comment on the disposition of nuclear weapons, submarines, et cetera," he said.
"But it is well known that ... as part of our overall defensive posture, there are submarines on patrol all around the world at any time. So it's not a question of anything new in what he (Timerman) is suggesting," Lyall Grant added.
Timerman said he welcomed Ban's offer to mediate in the dispute.
"Argentina agrees that the secretary-general should begin conversations with both countries so that we can sit down at a table ... to resolve this conflict in a peaceful way," he said.
Security Council action on Argentina's complaint is very unlikely given Britain's veto on the 15-nation panel.
Lyall Grant said Britain was open to bilateral talks with Argentina and there was no need for "third-party mediation." He said it was Buenos Aires, not London, that was preventing talks aimed at defusing the tensions between the two nations.
"We have always been open to dialogue with Argentina. ... We had a dialogue with Argentina and they broke it off," he said, adding that "we are not going to discuss sovereignty."
Lyall Grant said one of the problems in restarting talks with Buenos Aires was a 1994 amendment to Argentina's constitution requiring that the government seek sovereignty over the islands.
"We have made clear that we are not prepared to go into talks with the precondition that has been set in the Argentine constitution and discuss sovereignty over the heads of the people of the Falkland Islands," he said.
Argentina has also condemned British plans to deploy one of its most advanced destroyers, HMS Dauntless, to the area. It has also criticized the posting of Prince William, second in line to the British throne, to the islands as a military search-and-rescue pilot. (Reporting By Louis Charbonneau; Editing by Peter Cooney)