A U.S. government shutdown has begun, and it could impact travel plans, with potential airport delays and cancellations. The shutdown started Wednesday after President Donald Trump and Congress failed to agree on funding. Many airport employees are now working without pay. Geoff Freeman from the U.S. Travel Association warns of longer TSA lines and flight issues if the shutdown continues. Airports remain staffed, but the strain could worsen due to existing air traffic controller shortages. International travel is still possible, and passport processing remains mostly unaffected. Smithsonian museums and national parks are open, but with limited services.