The United States had harsh words for Iran on Monday, first in a speech by U.S. Secretary of State Mike Pompeo, followed by a late-night tweet on Sunday by U.S. President Donald Trump, who in no uncertain terms made it clear to Tehran that it should not threaten America—now or in the future.

In a speech to Iranian Americans in Southern California on Sunday, Pompeo noted the widespread corruption, deprivation and human-rights abuses Iran foists on its citizens, even associating its leaders to the mafia. He also noted that the first round of new U.S. sanctions will begin on Aug. 4, followed by another round on Nov. 4.

Later that day, Iran President Hassan Rouhani threatened the United States, saying “war with Iran is the mother of all wars.” It was followed by “Mr. Trump, do not play with the lion’s tail or else you will regret it.”

Rouhani also insinuated that the United States cannot prevent Iran from exporting oil and natural gas.

The president responded with a tweet that did not mince words: “WE ARE NO LONGER A COUNTRY THAT WILL STAND FOR YOUR DEMENTED WORDS OF VIOLENCE & DEATH. BE CAUTIOUS!”

Tehran is feeling pressure because of its struggling economy, made more uncertain after the Trump administration pulled out of the Iran nuclear deal in May. Money spent on operations throughout the Middle East, including on military forces based in Syria—a direct threat to Israel—is being felt on the domestic front, with the rial plunging this spring.

A longtime drought hasn’t helped matters.

Israeli Prime Minister Benjamin Netanyahu took to social media on June 18 to offer water-resource help to Iranians—a move that got a show of support from average Iranians. In an odd twist a few weeks later, an Iranian general accused Israel of manipulating the weather to steal the Islamic republic’s clouds and snow, thereby causing the drought.

The White House put the onus of the verbal standoff on Iran and Rouhani.

Meanwhile, Netanyahu continues to appeal to both the United States and Russia for the removal of Iranian forces from Syria, particularly near Israel’s northern border.