The emergency contraceptive is effective if taken within 72 hours of unprotected sex.
The US government has told a federal judge that it would make a branded version of the morning-after pill available to all women over-the-counter without age restrictions.
Under current laws, only girls aged 15 and older can purchase the morning-after pill without a prescription.
However in April, US district judge Edward Korman ruled that the drug should be made available over-the-counter and without age restrictions.
The women's rights groups said the federal government's decision to comply with a New York judge's ruling giving all girls easy access to emergency contraception could be "a move forward for reproductive justice."
However, the conservatives and other opponents of the pill's misuse argue the drug's availability takes away the rights of parents of girls who could get it without their permission.
In February this year a report said that the use of the morning-after pill in the US was on the rise. Some 11 percent of sexually active women had used the morning-after pill, up from 4 percent in 2002, according to the US Centers for Disease Control and Prevention.
One in four women aged 20-24 had used the drug, compared with one in nine women overall.
The CDC surveyed more than 12,000 females aged 15-44 from 2006-10.
Overall, about one in five women who had never been married had taken a morning-after pill, compared with just one in 20 married women.
Of the women who used the pill, 59 percent said they had done it only once, 24 percent said twice, and 17 percent said three or more times.
With agencies inputs