The United States said Friday it has ratified treaties under the Convention on Conventional Weapons (CCW), a formal step in a process undertaken by the former Bush administration.

The US State Deparatment said three treaties cover incendiary weapons, blinding laser weapons, and explosive remnants of war, while a fourth was an amendment that expands the CCW's scope to non-international armed conflicts.

"The United States took a leading role in negotiating these protocols and the amendment, has long complied with the norms contained in them, and is pleased to become a party to each of them," it said in a statement.

This action reaffirms our commitment to the development and implementation of international humanitarian law.

"The CCW and its protocols are part of a legal regime that regulates the use of particular types of conventional weapons that may be deemed to pose special risks of having indiscriminate effects or causing unnecessary suffering," it said.

"The CCW is a framework convention. States parties to the CCW negotiate protocols within this framework to regulate specific types of weapons. States ratify each protocol separately," it said.

Although Wednesday's ratification came a day after the inauguration of President Barack Obama, a state department spokeswoman said the timing was a coincidence.