Afghan President Hamid Karzai took small but public steps on Saturday to signal he was still friends with the United States after a war of words that tested their alliance.

In what appeared to be a choreographed effort to portray the relationship in the best light, Karzai visited the headquarters of General Stanley McChrystal, the U.S. and NATO commander, down the road from Karzai's own palace in central Kabul.

Karzai warmly greeted McChrystal and his aides, and attended a briefing of top brass of McChrystal's International Security Assistance Force (ISAF). Reporters were then invited to film the two men having lunch with a group of NATO officers.

Karzai's office also put out a statement saying President Barack Obama had written to Karzai to thank him for hosting his visit this month and confirming plans for Karzai to visit the United States on May 12.

"President Obama stressed in the letter that the United States will remain a strategic partner and hoped that Afghanistan and the United States work together on common goals," the statement from Karzai's palace said.

The moves came a day after the White House also signalled it wanted to bury the hatchet after the quarrel, brought on by anti-Western remarks Karzai made in a speech last week.

"We have gotten through this period," White House National Security Advisor James Jones briefed reporters on board Air Force One on Friday.

WHITE HOUSE "DISTURBED"

Karzai had sparked the row by accusing Western countries and officials of perpetrating election fraud in Afghanistan, in comments the White House called &

quot;disturbing" and untrue, and the State Department called "preposterous."

In other remarks in the last ten days, Karzai said there was a fine line between cooperation and occupation, and that Afghans had to see that their government were not "puppets."

Tensions between Karzai and the West come at a particularly awkward time, when the U.S.-led force is planning the biggest operation of the war to regain control of the southern city of Kandahar, Karzai's home town and heartland of the Taliban.

Under McChrystal's counter-insurgency strategy, U.S. officials want Karzai to be out in front as the public face of an operation meant to show the strength of Afghan institutions. They also want him to rein in his half-brother, a powerful official with extensive business ties in Kandahar.

Karzai's anti-Western remarks could hurt public support for the war in the United States and other countries with nearly 130,000 troops between them fighting in Afghanistan.

McChrystal's spokesman, Lieutenant-Colonel Tadd Sholtis, said Karzai's visit to the ISAF headquarters -- the first time he has attended an operational briefing there -- was a sign of the his increased leadership role in the conduct of the war.

"We're obviously working on the partnership here," he said. "I think it's just part of a larger engagement on his part with the strategic and operational direction of what we're doing."

Sholtis said Karzai's invitation to ISAF headquarters had been long-standing, and he could not comment on whether Karzai's decision to attend was motivated by a desire to show friendship after the strain the alliance had taken in the past two weeks.

Karzai had a frosty relationship with the Obama administration from the outset. It took a sharp turn for the worse late last year during a three-month stand-off over the Afghan presidential election. A U.N. backed watchdog threw out nearly a third of Karzai's votes on grounds of fraud.

The U.S. ambassador, Karl Eikenberry, wrote in a classified cable in November, later leaked, that Karzai was "not an adequate strategic partner."

En route to Obama's visit, Jones and other U.S. officials briefed that the U.S. President was going to press Karzai to do more to fight corruption and improve governance. Karzai complains that reports of corruption in Afghanistan are exaggerated and the problem is largely the fault of Western donors for poorly overseeing their aid budgets.

Obama's visit took place entirely under cover of darkness, and the U.S. president did not answer questions alongside Karzai, gestures that were seen by some Afghans as snubs.

(Additional reporting by Hamid Shalizi and Samar Zwak; editing by Andrew Roche)