India, July 15 -- Ronald Reagan Washington National Airport descended into its worst travel disruption in months on Wednesday, with the Federal Aviation Administration imposing a broad ground stop that grounded 303 flights and cancelled 118 more, a sweeping aviation shutdown tied to security requirements surrounding the White House visit of Iraqi Prime Minister Ali al-Zaidi.

Al-Zaidi met with US President Donald Trump for a high-stakes Oval Office meeting as their two nations navigated the most turbulent stretch of Middle East diplomacy in years.

The FAA issued the ground stop between 11:30 a.m. and 2 p.m., citing a "VIP" security-related event on its National Airspace System status page, a designation that aviation officials say typica...