By Shivansh Tiwary and Aishwarya Jain

July 2 (Reuters) - The number of Americans expected to travel into the weekend as the U.S. marks its 250th anniversary is expected to rise modestly this year, with a small fillip from the FIFA World Cup, even as high airfares and gas prices dampen some holiday plans.

Data from the AAA projects 72.2 million Americans will travel at least 50 miles from home for Independence Day between June 27 and July 5, up slightly from 71.8 million last year, though the rise is more modest than recent annual gains.

While Americans continue to travel in record numbers, the pace of growth is slowing as war-driven spikes in crude oil and jet fuel prices raise costs, squeezing household budgets and prompting travelers to rethink their plans, with an expected heat wave further complicating travel decisions.

However, the period is expected to test consumer resilience as higher travel costs clash with the nation's 250th anniversary festivities and the ongoing football World Cup.

"While the overall number of Independence Day travelers appears to be plateauing, we're still expecting record volumes this year," said AAA Travel's vice president, Stacey Barber.

AAA expects little change in the number of people traveling by road and air, while travel by buses, trains and cruises is likely to rise sharply.

Domestic flight capacity is flat from last year, which indicates that demand will be pretty similar to last year as well, OAG Aviation's John Grant said.

Meanwhile, major cities are expected to see the heaviest crowds. AAA cited strong demand for destinations such as New York, Chicago and Boston, where fireworks and holiday festivities are major draws.

Bookings for hotels in Washington, D.C., over the weekend have increased fivefold from last year, while average room rates are up 35%, according to online travel agency HotelPlanner.

"The notable anniversary is probably leading to less cancellations or changes even if heat is a concern for people," said Steve Schawb, CEO of Casago, a vacation rentals management company.

WORLD CUP KNOCKOUTS DRIVE HOST CITY DEMAND

Cities hosting high-stakes World Cup knockout matches are seeing a surge in demand, with vacation rentals jumping 68% in Miami ahead of a clash between Lionel Messi's Argentina and Cape Verde, as per data firm AirDNA.

Texas has also emerged as a winner, benefiting from a rare convergence of FIFA matches in Dallas and Houston as well as the 250th anniversary celebrations across the state.

The state has recorded the highest number of RV bookings on RVshare's platform for the July 4 weekend, according to the rental company.