U.S. President Barack Obama is hosting his closest ally, British Prime Minister David Cameron, at the White House for talks on Afghanistan, Syria, and global economic matters.

Mr. Obama hosted an elaborate arrival ceremony Wednesday morning for the official visit.

He called the relationship between the United States and Britain “one of the greatest alliances the world has ever known” and the “one constant” through the twists and turns of history.

“We stand together and we work together and we bleed together and we build together, in good times and in bad, because when we do, our nations are more secure, our people are more prosperous. The world is a safer and better and more just place. Our alliance is essential. It is indispensable to the security and prosperity that we seek, not only for our own citizens, but for people around the world.”

Mr. Cameron echoed Mr. Obama, calling the U.S.-British relationship “a meeting of kindred spirits.”

“The partnership between our countries, between our peoples, is the most powerful partnership for progress that the world has ever seen. That is why whenever an American president and a British prime minister get together, there is a serious and important agenda to work through. And today is no different. Afghanistan, Iran, the Arab Spring, the need for trade, for growth, for jobs in the world economy, the biggest issues in the world — that is our agenda today.”

Mr. Obama and Mr. Cameron were also expected to discuss the upcoming NATO and G-8 summits. Wednesday night, the prime minister will be the guest of honor at a formal White House dinner.

The two leaders wrote in The Washington Post newspaper Tuesday that the U.S.-British alliance is a “partnership of the heart, bound by the history, traditions and values” that the two countries share.

They said they are working with other global economic powerhouses to create jobs, sustain the global recovery, and resolve Europe's debt crisis.

On Tuesday, Mr. Obama shared his passion for basketball with Mr. Cameron, treating him to a U.S. springtime tradition — a college tournament game in Ohio between Western Kentucky University and Mississippi Valley State.

It was the first basketball game Mr. Cameron has attended. He told a television reporter that the game moved fast and the rules are a bit confusing.