WASHINGTON — The Obama administration, under intense political pressure from Capitol Hill and elsewhere, is engaged in a vigorous debate over whether to reverse course and join an international treaty banning land mines, administration officials said this week.

In re-examining the issue, the administration is stepping back into the glare of a perennial cause that has captured the attention of world leaders, royalty and celebrities. It is also inviting another internal debate that pits the Pentagon against other parts of the administration.

The policy review, which officials expect to be completed this summer, could result in the United States pledging to abide by the treaty’s provisions even if it does not join it. That would be a striking disavowal of its announcement last fall that it would stick to the Bush administration’s refusal to join the agreement, known as the Ottawa Treaty.

It would also mollify critics, chiefly Senator Patrick J. Leahy, Democrat of Vermont, who called the earlier decision a “default of U.S. leadership and a detour from the clear path of history.” Mr. Leahy, who expressed his dismay to President Obama, said on Friday that he was glad the issue was getting “the kind of attention it should have been getting then.”