US President Joe Biden speaks to reporters before boarding Marine One on the South Lawn of the White House
US President Joe Biden speaks to reporters before boarding Marine One on the South Lawn of the White House AFP

US President Joe Biden said Thursday that air strikes by Pakistan and Iran on each other's territory showed Tehran was not "well-liked", as the White House warned against any escalation.

Tensions between nuclear-armed Islamabad, a key US ally, and Washington's foe Tehran have soared after Iran struck alleged militant targets in Pakistan and Pakistan responded in kind.

The situation has also added to broader tensions in and around the Middle East, where Iran's proxies are in confrontation with Israel and the United States following the Hamas attacks on Israel on October 7.

"As you can see, Iran is not particularly well liked in the region," Biden told reporters at the White House when asked about the clashes.

Biden said the United States was now trying to understand how the Iran-Pakistan situation would develop, adding: "Where that goes we're working on now -- I don't know where that goes."

White House National Security Council spokesman John Kirby said the United States was monitoring the situation "very, very closely" and was in touch with Pakistani officials.

"These are two well-armed nations and again we don't want to see an escalation of any armed conflict in the region, certainly between those two countries," Kirby told journalists aboard Air Force One.

Islamabad had a right to defend itself after the initial strikes by Iran, which Tehran said had targeted a Sunni Muslim extremist group behind a series of attacks in Iranian territory.

Pakistan responded with strikes in Iran against what it said were separatist militants backing an insurgency in its restive southwestern province of Baluchistan.

"They were struck first by Iran, which was obviously another reckless attack, another example of Iran's destabilizing behavior in the region," added Kirby.

Kirby said he was "not aware" that Islamabad had notified Washington before striking Iran.

He would not comment when asked if the United States would provide support for Pakistan, which is a major non-NATO ally but long had tense relations with Washington over claims it covertly backed the Taliban in Afghanistan.