Israel is to seek a UN opinion on its maritime borders with Lebanon in the Mediterranean, where lucrative offshore gas fields have been found, Foreign Minister Avigdor Lieberman said on Sunday. \"We will soon be presenting the United Nations headquarters in New York with our position on our maritime borders,\" Lieberman told Israeli public radio. \"We have already concluded an agreement on this issue with Cyprus... Lebanon, under pressure from Hezbollah, is looking for friction, but we will not give up any part of what is rightfully ours,\" he added. Israel has been moving to develop several large offshore natural gas fields in the Mediterranean that it hopes could help it to become an energy exporter. But its development plans have stirred controversy with Lebanon, which argues the gas fields lie inside its territorial waters. Israel does not have officially demarcated maritime borders with Lebanon, and the two nations remain technically at war. But Lieberman said the Jewish state had \"very strong arguments under international law\" for its position, adding that the foreign and justice ministries had been working together to set them out. A senior Israeli official, speaking to AFP on condition of anonymity, said that at their regular cabinet meeting on Sunday ministers would endorse a map of Israel\'s maritime borders in the Mediterranean to be presented to the UN. According to the Haaretz newspaper, the Israeli claim would include some areas that Lebanon claimed in its submission to the UN in August. The two biggest known offshore fields, Tamar and Leviathan, lie off Israel\'s northern city of Haifa. Tamar is believed to hold at least 8.4 trillion cubic feet of gas (238 billion cubic metres), while Leviathan is believed to have reserves of 16 trillion cubic feet (450 billion cubic metres). In recent weeks, an Israeli company has also announced the discovery of two new natural gas fields, Sarah and Mira, around 70 kilometres (45 miles) off the city of Hadera further south.