Spain says Israeli fire killed a Spanish UN peacekeeper serving in south Lebanon and called on the United Nations to fully investigate the violence.

"It is clear that this was because of the escalation of the violence and it came from the Israeli side," Spanish UN ambassador Roman Oyarzun said.

The Spanish envoy said he had asked for a full investigation during an emergency meeting of the council called by France to discuss ways to defuse tensions between Israel and Lebanon. The violence raised fears of another all-out conflict between the two countries, who fought a month-long war in 2006, in a region already wracked by fighting in Syria and Iraq.

Secretary General Ban Ki-moon called for "maximum calm and restraint", urging all sides to "act responsibly to prevent any escalation in an already tense regional environment", a UN statement said.

Tension in the area has been building, especially after an Israeli air strike on the Syrian sector of the Golan Heights killed six Hezbollah fighters and an Iranian general on January 18.

"Our objective is to engage toward de-escalation and to prevent further escalation of the situation," French Ambassador Francois Delattre told reporters.

France presented a draft statement to council members but after meeting for over an hour, the council issued a terse condemnation of the peacekeeper's death and made no mention of de-escalation efforts. Discussions on the council statement were continuing.

The clashes began when Hezbollah fired an anti-tank missile at a military convoy in the Israel-occupied border area, prompting Israel to respond with air and ground strikes.

The 36-year-old Spanish corporal serving in the UN interim force UNIFIL in southern Lebanon was killed in the exchange of fire. The 10,000-strong UNIFIL mission said it had observed six rockets fired towards Israel from southern Lebanon and that Israeli forces "returned artillery fire in the same general area".

Israel's ambassador to the UN said in a letter that Israel was ready to take all necessary measures to defend itself and demanded that the council condemn Hezbollah.