Taoiseach Bertie Ahern has praised Hillary Clinton's role in the Northern Ireland peace process, rejecting criticism from her opponents that she had not been central to the process.

Mr Ahern was speaking in Washington after a series of events to mark St Patrick's Day, during which he had a one hour meeting with US President George W Bush.

Mrs Clinton has come under fire from Barack Obama's campaign team, who have suggested she has exaggerated her role in the peace process in Northern Ireland.

Mr Ahern met Senator Clinton this morning and also had a telephone conversation with her rival for the Democratic nomination Barack Obama.

Mr Ahern praised Senator Clinton's role in the peace process, saying it would be very unfair to try to take that away from her  and he said Senator Obama had accepted that point during their phone call.

Amnesty for illegal Irish 'not on'

The Taoiseach also said the idea of an amnesty for Irish illegal immigrants in the US is 'not on' and that people should stop giving the impression that it is a possibility.

Mr Ahern was speaking to journalists after attending a lunch on Capitol Hill hosted by the Speaker of the House of Representatives, Nancy Pelosi.

He said people talking up the prospects of such a deal were 'sitting in the bar talking nonsense'.

Mr Ahern said it had not been possible to introduce the comprehensive immigration reform bill sponsored by Senators Ted Kennedy and John McCain, but there might be a chance of achieving some progress, perhaps next year.

Earlier, President George W Bush promised continuing US support for the Northern Ireland peace process, particularly through next May's investment conference in Belfast.

He was speaking after meeting Mr Ahern at the White House, where a St Patrick's Day shamrock ceremony also took place.

Mr Bush has promised continuing US support for the Northern peace process, particularly through next May's investment conference in Belfast.

Mr Ahern and Mr Bush had a one-hour discussion in the Oval Office, covering a wide range of issues, but focusing in particular on Northern Ireland.

President Bush said afterwards that the US would continue its strong support for the peace process, promising to send a high-powered delegation to the investment conference in May.

He said this would demonstrate US support for the people of Northern Ireland, as well as offering good investment opportunities.

Before presenting Mr Bush with the traditional bowl of shamrock, Mr Ahern thanked him for his support over the past eight years, saying that any time the government needed help, Mr Bush had provided it.