KANDAHAR, Afghanistan - Defence Minister Peter MacKay reinforced Ottawa's dismay with Hamid Karzai's Taliban musings in face-to-face meetings Thursday with senior members of the Afghan president's cabinet.

Even as he expressed his frustration to Afghanistan's defence and interior ministers, however, MacKay pledged an additional 90 Canadian soldiers and civilians to help train soldiers and police.

"We took every opportunity with Afghan ministers and Afghan officials to express Canada's disappointment over the president's comments," MacKay said from Kabul.

"Canada does not want to see the people of Afghanistan, who we have made a commitment to help and protect, punished because of ill-conceived remarks by President Karzai."

The comments come only one day after Prime Minister Stephen Harper took Karzai to task for a recent string of anti-Western rants.

According to reports that have been denied by a Karzai spokesman, his comments included a warning to members of parliament that he might join the Taliban if pressure from allies to curb corruption doesn't ease.

The White House has also expressed its dismay, and hinted that it would cancel a scheduled visit from Karzai next month if the comments continue.

Nonetheless, the troubling rhetoric didn't prevent MacKay from stepping forward with extra soldiers, civilian staff college personnel and police trainers. Some of the reinforcements will be sent to the NATO training centre in Kabul, while others are expected to bolster training forces in Kandahar.

The additions bring the number of Canadian troops, aircrew and civilian trainers in Afghanistan to well over 3,000.

MacKay says the trainers will stay until Canada begins drawing down its forces, starting in July of next year.

Building a capable Afghan security force, one that can conduct operations on its own in most of Kandahar province, is one of the Canadian government's key priority goals before the end of the combat mission.

A recent report to Parliament cast doubt on whether the goal could be achieved because of a stubbornly high attrition rate among Afghan units.

But in a meeting Thursday with Defence Minister Gen. Rahim Wardak, MacKay said he was told recruiting was up, noting that the request for additional trainers came directly from the Afghans.

"They're recruiting heavily and they're obviously in an accelerated growth period; as a result they need more trainers to address those swelling numbers."

Almost as if on cue, Afghan police said Thursday they had thwarted a major attack in Kabul, arresting five would-be suicide bombers -- the largest such group ever apprehended in the capital.

"If this team had made it through, it would have been a disaster," said Abdul Ghafar, deputy commander of the Afghan National Police crisis unit.

Police, acting on intelligence, stopped the suicide bombers -- part of the al-Qaida-linked Haqqani network, Ghafar said -- as they were travelling in an SUV in the southeastern part of the city.

"Today's operation marks a big success," he said. "Our ability to uncover such plots is improving day by day."

In order to speed up the expansion of the Afghan army, NATO set up a separate training command last year, which is headed by U.S. Lt.-Gen. William Caldwell.

Plans call for Afghanistan's military to expand to more than 170,000 soldiers by October 2011, up from 98,000. Police numbers will grow to 134,000 from more than 90,000 today.

Within five years, the ranks of the Afghan security forces are expected to reach 240,000 soldiers and 160,000 police officers.

NATO countries have pledged nearly 500 new instructors, but Caldwell recently said another 660 will be needed to fulfil requirements.

Getting countries to commit training forces has been a struggle almost from the outset, and NATO has been forced to hire private security companies to do some of the instruction, Caldwell noted.

Trainers account for roughly two per cent of more than 100,000 foreign troops in Afghanistan.