The escalation between Israel and Lebanon's Hezbollah is nearing a full-fledged war, the European Union's foreign policy chief said on Monday.

"This situation is extremely dangerous and worrying. I can say that we are almost in a full-fledged war," Josep Borrell told reporters.

"If this is not a war situation, I don't know what you would call it," he added, citing the increasing number of civilian casualties and the intensity of military strikes.

Borrell said efforts to reduce tensions were ongoing, but Europe's worst fears about a spillover were becoming a reality. He emphasized that civilians were paying a high price and that all diplomatic efforts were needed to prevent a full-blown war.

"Here in New York is the moment to do that. Everybody has to put all their capacity to stop this path to war," he said.