Sarah Sakha graduating from Princeton in 2018.

NBC: Escalating tensions between Tehran and Washington have rattled Sarah Sakha, 23, an Iranian American who recently graduated from college in the U.S. and got a job at a nonprofit in New York.

She fears for the safety of relatives and friends in Iran. She worries that few Americans recognize the perils of another military conflict in the Mideast, or what she describes as "Iraq 2.0."

Alarmed by the flurry of news alerts, she has broken down crying at work.

"The constant emotional stress and terror I feel as a first-generation Iranian American is undeniable," Sakha said. "I think it's especially terrifying how things can change overnight, literally."

Sakha is among nearly 500,000 people in the U.S. of Iranian ancestry, many of whom are closely following developments as the U.S. and Iran head toward a possible clash.

President Donald Trump on Friday said the U.S. was "cocked and loaded" to retaliate against Iran for downing a U.S. surveillance drone. But he said he called off the strike minutes before it was set to launch when he heard 150 civilians could die, he said.

In an interview with NBC News' Chuck Todd on Friday, Trump said a plan was "ready to go subject my approval."

As the crisis mounts, several Iranian American civic organizations and advocacy groups are on high alert, with some calling for the U.S. and Iranian governments to exercise caution before the situation spirals into violence.

The National Iranian American Council, a Washington-based group that advocates for improved relations between the two countries, pleaded for "restraint."

"Both Trump and his inner circle and Iran’s leadership should recognize that the U.S. and Iran have entered an escalation spiral. Adding fuel to the fire risks stoking this crisis to the point of no return," Jamal Abdi, the group's president, said in a statement.

"The night is always darkest before the dawn. We urge all leaders to put their countries’ best interests in mind and firmly step away from the path to war," Abdi added.

The American Iranian Council, a public policy group that focuses on diplomacy surrounding Iran, released a similar statement this week, faulting both the U.S. and Iran for stoking tensions.

"AIC calls on both countries to immediately cease their aggressive and escalating rhetoric," the group said in a statement.

It was not immediately clear whether any major Iranian American advocacy groups planned to organize aid to families in Iran, many of whom have been separated from loved ones in the U.S. by the Trump administration's travel ban or struggled under tough economic sanctions on their country.

Dealing with the icy relationship between the U.S. and Iran is nothing new for many Iranian Americans. They saw the nuclear accords under President Barack Obama give way to more openly hostile rhetoric from Trump, who has accused the Iranian regime of doing "bad, bad things.*

Ali Ghambari, founder of the Iranian American Community Alliance, a Seattle-based nonprofit, said he would not be surprised if American groups provided financial assistance to Iranian nationals during a hypothetical conflict.

Ghambari, 60, who has lived in the U.S. since 1979, said he was grateful that Trump was "not moving fast" on a standoff with Iran. He added that he would prefer a diplomatic resolution.

But not all Iranian Americans were averse to the U.S. taking a hard line against Iran.

At a gathering in front of the White House on Friday, dozens of Iranian Americans rallied for regime change in Tehran, with some calling for the overthrow of the ruling government.

Ahmad, an Iranian-American man who did not want to provide his full name because of concerns about his family's safety, said he blamed the Iranian regime for the deaths of his brothers, including one he says was tortured in state prison.

He said he did not expect that will be a war. But the U.S., he added, will "have to take firm action."