The killing of a senior leader of the Islamic group Hamas, Ismail Haniyeh, has raised international concerns that it may escalate tensions in the Middle East.

Hamas said on Wednesday that Haniyeh was killed in an Israeli attack during his visit to Iran's capital, Tehran. Hamas is fighting the Israeli military in the Gaza Strip.

Israel has not confirmed that it killed Haniyeh.

In a statement released on Wednesday, United Nations Secretary-General Antonio Guterres called on the international community to work together to advance diplomatic action for regional de-escalation.

Referring to the killing of Haniyeh, he said it represents "a dangerous escalation at a moment in which all efforts should instead be leading to a ceasefire in Gaza, the release of all Israeli hostages" and other goals.

White House National Security Communications Advisor John Kirby was asked about the US government's assessment of the Middle East situation following Haniyeh's death.

Kirby said, "We don't believe that an escalation is inevitable. And there's no signs that an escalation is imminent." But he added that the government is keeping a close watch on the situation.
Kirby also said the US will continue working toward a ceasefire deal in Gaza and the release of hostages held by Hamas.

On Tuesday, the Israeli military announced that it killed a senior Hezbollah commander in a targeted airstrike on the Lebanese capital of Beirut.
The Lebanon-based Shia Muslim group, which has shown solidarity with Hamas, confirmed the commander's death on Wednesday.

The US State Department on Wednesday raised the travel advisory for Lebanon to the highest level of 4. It urged US citizens not to travel there due to rising tensions between Hezbollah and Israel.