British singer P. J. Harvey released her first book of poetry on her 46th birthday on Friday -- based on journeys to Afghanistan, Kosovo and the United States.

The book, entitled "The Hollow of the Hand", is a collaboration with photographer Seamus Murphy and is based on travels between 2011 and 2014.

"Gathering information from secondary sources felt too far removed for what I was trying to write about," Harvey said in a statement released by the book's publishers, Bloomsbury.

"I wanted to smell the air, feel the soil and meet the people of the countries I was fascinated with," she said.

Murphy said: "It is our look at home and the world."

The two friends already worked together on Harvey's last album "Let England Shake", for which Murphy took photographs and shot films.

In January and February, two-time Mercury Prize-winner Harvey recorded her ninth studio album in front of an audience hidden by one-way mirrored glass, as if an exhibition in a gallery.

The pair appeared together late Friday at an evening of poetry, music and photography in London, where journalist Anthony Loyd, hosting the event, asked Murphy how he felt taking a "cherished English legend" to war-torn Afghanistan.

"I just thought if I bring her around to places I would go, foundries, weird chicken coops, I thought that's what Polly would like," he told the packed Royal Festival Hall, using Harvey's first name.

He said they told people they were reporters, "which is true".

"We have a journalistic approach. Polly will interview, she will observe, I will photograph," he said, while noting the work did not have the same restrictions as traditional journalism, and was "not answerable to an editor".