WASHINGTON (AFP) - President Barack Obama and Britain's Prime Minister David Cameron were to begin two days of meetings at the White House on Thursday focusing largely on joint anti-terror efforts, in the wake of last week's attacks in Paris.

"The President is looking forward to discussing with him a wide range of issues, some of them related to national security," White House spokesman Josh Earnest told reporters on Wednesday, as he hailed Washington's "special relationship with the United Kingdom."

"I'm confident that the close counterterrorism partnership that we have with the United Kingdom will be discussed," Mr Earnest said.

The spokesman said Mr Obama and Mr Cameron would have a "working dinner" late on Thursday, followed by "a whole set of formal meetings" on Friday.

"I'm confident that they will discuss the ongoing campaign against ISIL. The British military has made significant commitments to that effort. We're deeply appreciative of them."

The two leaders, in a jointly-written opinion piece published Wednesday in Britain's The Times newspaper, vowed to present a united front against Islamic extremists after Islamist gunmen killed 17 people in three days of attacks in and around Paris last week, including a massacre that claimed 12 lives at the Charlie Hebdo satirical weekly.

"We will continue to stand together against those who threaten our values and our way of life," Mr Obama and Mr Cameron wrote.

"We will defeat these barbaric killers and their distorted ideology which tries to justify the murder of innocents."

The visit is the fourth between Mr Obama, 53, and Mr Cameron, 48, who also are expected to tackle various economic issues.

The two leaders will work on a massive trade deal between the United States and the European Union which hit a road block this week.

Other items expected to figure on their agenda are the falling price of oil, Iran nuclear talks, cyber security and the global fight to contain the Ebola virus.