Prime Minister David Cameron and President Barack Obama have agreed that the UK and US are "on the same page" on Afghanistan.
The agreement, made during a half-hour phone call between the two leaders on Tuesday night, came days after Mr Obama's review of Afghanistan and Pakistan which found that Nato-led forces are making headway against Taliban insurgents and restated the goal of handing over security responsibility to Afghan forces by 2014.
Mr Cameron also briefed the president on Monday's arrests of 12 suspects by anti-terror police in London, Cardiff, Stoke and Birmingham, said Downing Street in a statement shortly after the call.
A Downing Street spokesman said: "The Prime Minister spoke to President Obama by phone for half-an-hour.
"The discussion focused on Afghanistan. The Prime Minister began by reiterating his condolences on the death of (US envoy) Richard Holbrooke.
"The Prime Minister then welcomed the United States' review on Afghanistan and Pakistan.
"The leaders agreed that Britain and America were 'on the same page'. 2010 had been a year of progress, on which the international community needed to build in 2011.
"They paid tribute to the immense bravery and professionalism of British, US, and international forces.
"There was a discussion of the Middle East peace process, on which the leaders agreed to continue to co-ordinate closely to sustain the process and deliver a two-state solution.
"The Prime Minister also briefed the President on the counter-terrorism arrests made in the UK."