If a US government shutdown goes on long enough, it could throw a wrench in travel plans, potentially leading to longer airport wait times, flight delays, and even cancellations.

Australian travellers heading to the United States are being warned to expect disruptions with some tourist attractions closed, flights disrupted and national parks and museums affected.

Despite modest growth, the forecast predicts the decline in international visitors threatens U.S. jobs and the economy.

Canadian travelers have flocked to Mexico in recent months after the U.S. introduced sweeping tariffs against their country.