If the U.S. entered the conflict between Iran and Israel, Tehran could target American military assets in the region, experts have told Newsweek.

The mounting destruction and death toll in the conflict between Israel and Iran is raising fears of broader escalation, with the United States caught in the conundrum of military involvement in the Middle East's most perilous confrontation since the Gulf War.

As Israel and Iran trade missile strikes, Iran is issuing a direct threat to the United States that further support of Israel will result in direct strikes on U.S. military bases in the region. NBC’s Matt Bradley reports for Sunday TODAY.

Israel has escalated its bombardment of Iranian cities, including Tehran's state television headquarters; Iranian missiles have struck Tel Aviv.

If nuclear negotiations fail and conflict arises with the United States, Iran will strike American bases in the region, Defence Minister Aziz Nasirzadeh said on Wednesday, days ahead of a planned sixth round of Iran-U.

Tehran said American bases in the Middle East could face reprisals if the U.S. helped repel Iranian attacks on Israel.

President Donald Trump denied early on Tuesday having had contact with leaders in Iran, saying he hadn't reached out about a potential ceasefire and that he was "not too much in the mood" to negotiate with Iran.

Iran's strikes against Israel will continue, with targets set to expand to include U.S. bases in the region in the coming days, Iran's Fars news agency reported on Saturday, citing senior Iranian military officials.