LONDON, May 13 (Reuters) - Britain and the United States have agreed to collaborate on future commercial spaceflight missions, boosting opportunities for firms from both countries to operate from spaceports in either, the British government said on Friday.

Britain said the partnership, signed by transport minister Grant Shapps and his U.S. counterpart Pete Buttigieg in Washington this week, would make spaceflight easier and cheaper.

The new declaration "lays the foundation for rockets, high-altitude balloons and spaceplanes to lift off from spaceports across the UK very soon," the British government said in a statement.

The partnership will see the two countries collaborate on the licensing of commercial space launches, and provide benefits including critical defence security and better weather forecasts, to enabling television services and more efficient transport, Britain said.

The United States was proud to launch a partnership with bringing more of the benefits of commercial space travel to its workers, businesses and communities.

"Commercial space travel is growing swiftly, and it's our responsibility to ensure that these innovations advance safely, encouraging them to develop in ways that benefit us all," Buttigieg said in a statement.