The US put intense pressure on the Irish government to sanction a bigger role for the Republic's troops or gardai in Afghanistan, leaked secret papers reveal.

And the US also wanted special status for troops passing through Shannon Airport on their way to Afghanistan and Iraq.

Confidential documents, obtained by the Irish Independent from the whistleblowing website WikiLeaks, reveal the extent of the pressure placed on Irish officials by the US Embassy in Dublin.

Despite the negative reaction from several Irish contacts, US Ambassador Dan Rooney reported back to Washington: "We will keep pressing the Irish on additional police or troop trainers and development assistance."

At one stage, a senior Department of Defence official, who is named in the leaked US cable, told the embassy that Ireland had been exploring opportunities to contribute military trainers to Afghanistan but faced security-related and political difficulties.

He outlined discussions with Canada on sending two Irish soldiers, probably a lieutenant or captain and an NCO, as instructors in a Canadian-led training programme for junior officers and NCOs.

Other participants would be from Sweden and Finland.

But the Defence official said the idea had been rejected as too dangerous since Canada would not be able to provide logistical support such as secure housing or transportation.

The project's advantage, according to the official, would have been its political palatability in a country protective of its neutrality.

The US cable -- sent in December 2009 -- quoted the Irish official as stating his soundings confirmed that working outside NATO with the Canadians and fellow neutral countries Sweden and Finland would have met with the approval of the "pacifist-oriented" Green Party and of the Oireachtas.

The official said he had heard the previous day that Irish trainers might participate in a similar -- but NATO-led -- training mission but that would also have to pass scrutiny on security grounds and be approved by the Dail before getting a go-ahead.

He said Dail approval would be more difficult because of the NATO connection but he felt it could probably be won over with the argument that Ireland must support the international community's efforts to build the capacity of the Afghan forces to provide for their own security.

Embassy officials also raised the possibility of concluding an agreement with Ireland that would grant US troops special status as they travelled through Shannon on the way to and from Afghanistan and Iraq.

However, the senior Defence official pointed out that giving US troops any sort of special status would spark a major public debate.

He said this would awaken the opposition of an Irish populace that was very jealous of Ireland's neutrality, according to the cable.

The official added it could also jeopardise Irish national security, since it would highlight Ireland's help to the US and expose it to possible terrorist attacks by al-Qa'ida or associated groups.

He believed the current informal arrangement should remain in place.