After failing to alert Congress about the planned airstrike that killed Iranian military leader Qassem Soleimani, Donald Trump took to Twitter on Sunday afternoon to alert Congress that he would order the military to “fully strike back” against Iran if they attack American citizens. In response, Washington leaders sarcastically replied with a scathing tweet of their own.

According to HuffPost, Congressional leaders admonished Trump last week to honor the War Powers Act of 1973 and alert lawmakers before entering into an armed conflict with a foreign nation, which some argue may happen after Trump ordered the killing of Soleimani. In response, he sent a tweet notifying lawmakers that he was planning to respond harshly to any retaliation from Iran as a result of killing the prominent leader.

“These Media Posts will serve as notification to the United States Congress that should Iran strike any U.S. person or target, the United States will quickly & fully strike back, & perhaps in a disproportionate manner,” he wrote. “Such legal notice is not required, but is given nevertheless!”

The House Foreign Affairs Committee, which oversees investigations and crafts laws that relate to foreign nations, slammed Trump’s tweet with a sarcastic response.

“This Media Post will serve as a reminder that war powers reside in the Congress under the United States Constitution. And that you should read the War Powers Act. And that you’re not a dictator,” it wrote.

The committee wasn’t the only one to respond to Trump’s tweet. Many people were shocked that the president was using a social media platform to essentially declare war against a foreign nation. Others warned the president to respect the constitution.

Eugene Gu, CEO of CoolQuit, informed the president that Roosevelt went to Congress when Japan bombed Pearl Harbor.

With the drone airstrike that took out a two-car convoy near Baghdad’s international airport, Trump has escalated tensions both in the Middle East and within the U.S. government. Democrats, including House leader Nancy Pelosi, called out Trump for not notifying Congress within 48 hours of initiating conflict in the region as the War Powers Act requires. While Trump did issue a classified report, it didn’t include the usual information that is present in these types of situations.

“This classified War Powers Act notification delivered to Congress raises more questions than it does answers,” Pelosi said.

She went on to argue that the report raised questions about the justification for engaging in the conflict that could potentially destabilize the region. She also said that classifying the document seemed to indicate that the Trump administration was hiding information from the citizens of the U.S.

Trump has warned Iran that if it retaliates against the U.S., his administration had identified 52 cultural sites that would be hit by the U.S. military. People warned the president that attacking cultural sites and places of worship is considered a war crime.