President Donald Trump left the question of whether the United States will join Israeli strikes on Iran up in the air Wednesday, as he said that Tehran had reached out to seek negotiations.

"I may do it, I may not do it. I mean, nobody knows what I'm going to do," Trump told reporters as he supervised the installation of a new flagpole on the White House South Lawn.

Tropical storm Erick, bearing down on the southwestern coast of Mexico on the Pacific Ocean, strengthened into a hurricane Wednesday, the US National Hurricane Center said.

The hurricane is 255 kilometers (155 miles) from the town of Puerto Angel in the southern Mexican state of Oaxaca and is packing maximum sustained winds of 120 kilometers an hour (75 mph), the meteorological center said.

Israel's military said it was striking military targets in Tehran on Wednesday, as AFP journalists reported hearing blasts in the north and east of the Iranian capital.

The Israeli air force "is currently striking military targets belonging to the Iranian Regime in Tehran," the military said in a statement, on the sixth day of the war between the arch foes.

Iran's supreme leader Ayatollah Ali Khamenei said Wednesday the nation would never surrender as demanded by President Donald Trump and warned the United States it would face "irreparable damage" if it intervenes in support of its ally.

The speech came six days into the conflict, with Trump demanding Iran's "unconditional surrender" while boasting the United States could kill Khamenei and fueling speculation about a possible intervention.

Hundreds of people gathered outside a London court Wednesday in a show of support for the provocative Irish rap group Kneecap as one of the singers appeared charged with a terror offense for allegedly promoting Lebanon's Hezbollah.

Liam O'Hanna, 27, known by his stage name Mo Chara, was charged in May after being accused of displaying a Hezbollah flag during a London concert in November.

The United States is setting up a round-the-clock task force to help Americans in the Middle East during the Israel-Iran conflict, officials said Tuesday.

U.S. President Donald Trump met his National Security Council on Tuesday to discuss the Iran-Israel war, the White House said, as the U.S. leader considered whether to join Israel's air campaign against Tehran.

Israel said it struck a nuclear site near Tehran on Wednesday, while Iran said it fired hypersonic missiles as the arch foes traded fire for a sixth day.

Hours after U.S. President Donald Trump demanded Iran's surrender, supreme leader Ayatollah Ali Khamenei vowed his country would show "no mercy" towards Israel's leadership.

U.S. President Donald Trump dramatically stepped up his rhetoric against Iran's supreme leader Tuesday, saying on social media that the United States knows where Ayatollah Ali Khamenei is located but will not kill him "for now."

In another post, Trump also appeared to demand Iran's "UNCONDITIONAL SURRENDER!" as he fueled questions about whether the United States would join Israel's attacks on Tehran's leadership and nuclear facilities.

Air raid sirens sounded in the Tel Aviv area and parts of northern Israel on Tuesday, the military said, after warning of a fresh salvo of incoming missiles fired from Iran.

"A short while ago, sirens sounded in several areas across Israel following the identification of missiles launched from Iran toward the state of Israel," a statement from the military said, with residents of the Tel Aviv area and parts of the north urged to seek shelter.