By Vincent Dowd
BBC News, Washington
President George W Bush has restated his personal opposition to abortion on the 35th anniversary of its legalisation in the US.
Mr Bush's message was taped and later broadcast to other marchers
Mr Bush was speaking before thousands of anti-abortion activists attended a March For Life rally in Washington.
"You're here because you know that all life deserves to be protected... I'm proud to be standing with you," Mr Bush said to organisers of the annual march.
There are an estimated 1.2 million abortions in America annually.
White House invitation
On 22 January 1973, the US Supreme Court legalised abortion in America when it ruled on the Roe versus Wade case.
In that case the court decided under the constitution individual states did not have the right to prevent abortion.
Each year there is a well-attended March for Life rally in Washington to urge the Supreme Court to overturn its ruling.
Campaigners hope a court which has become more conservative under Mr Bush is more likely now one day to do that.
Mr Bush invited 200 of the marchers to the White House to offer his support. He said each unborn child was a separate individual with his or her own genetic code.
"America is better than this, so we will continue to work for a culture of life," he said. A taped version was broadcast to other demonstrators later.
Abortion reform has not featured large in the current campaign for the presidency but it retains the potential to become an issue.
Of the Republicans only the former New York Mayor, Rudy Giuliani, does not want to overturn the Roe versus Wade ruling - and this has alienated some in his party.