Mr Trump said he was abortion except in cases of rape, incest or a "serious health risk" to the mother.
His stance on what is a divisive election issue in the US emerged days after Alabama passed a law all cases.
A pro-choice rally is planned later on Sunday in protest at the new measures.
Supporters of Alabama's abortion ban say they expect the trial to be blocked
They are the highest court in the country ̵
Sixteen other states are also seeking to impose new restrictions on abortion.  Mr Trump, whose position on abortion has shifted over the years, has been silent on the Alabama restrictions until today.
"I am very strongly pro-life, with The three exceptions – rape, incest and protecting the life of the mother – the same position taken by Ronald Reagan ", he said.
Neil Gorsuch and Brett Kavanaugh, 19659010]
"We have come to the end of the last two years with 105 wonderful new federal judges (many more to come), two great new supreme court justices … and a
Abortion is controversial in the US, with evangelical Christians in particular forming a nucleus of voters who want to restrict, or even outlaw, the procedure completely.
19659010] Mr. Trump has adjusted his stance over the years. In 1999, he said, "I'm very pro-choice." I hate the concept of abortion. I hate it. I hate everything it stands for. I cringe when I listen to people believe in choice. "
But in March 2016, he clarified that his position was" pro-life with exceptions. "
On Saturday he tweeted that Republicans must unite with" win for life in 2020. "
Senior Democrats have said that the issue will be an important one in the 2020 presidential campaign.
Massachusetts senator and Democratic presidential candidate Elizabeth Warren responded to Alabama's abortion ban by saying: "This ban is dangerous and exceptionally cruel – and the bill's Roe v Wade.
"I've lived in that America and let me tell you: We are not going back – not now, not ever. We want to fight this. And we want to win. "
Since abortion the Supreme Court ruling on abortion in 1973, the number of abortion clinics has dropped in many US states, and in 2017, six states reportedly had just one abortion clinic in operation.
This article was previously published under the symbol "The Guttmacher Institute."
According to the Guttmacher Institute – a group of reproductive rights – none of these bans are yet in effect
In January, New York, the right to terminate a pregnancy is pronounced after 24 weeks in certain cases.