US President Barack Obama and his Russian counterpart Dimitry Medvedev have agreed to sign a new nuclear arms reduction treaty, following months of protracted negotiations.

In a phone call on Friday morning, Obama and Medvedev committed their nations to the arms deal, which will lead to a significant decrease in the numbers of weapons deployed by both sides.

The START2 treaty is scheduled to be signed by both Presidents at a ceremony in the city of Prague, on Thursday, April 8, according to the White House.

The treaty calls for both sides to reduce the stockpiles of their most dangerous weapons, those already deployed and ready to launch at long-range targets, by about 30% for Russia, and 25% for the US, limiting each side to about 1 550 such missiles.

START2, which will have to be ratified by the US Senate and in Russia, will replace the original, 19-year-old agreement between the two countries that expired in early December 2009, and the Moscow treaty of 2002. Both Presidents had agreed they would abide by their parameters until a new treaty could be finalized.

US administration officials have described the achievement as a hard-fought victory in Obama's efforts to limit the spread of nuclear weapons. In a 2009 speech in Prague, he had pledged that the US would lead by negotiating the new treaty with Russia.

The treaty faces some skepticism in the US Senate, where it will need Republican support to secure the 67 votes required for ratification. Several key senators have recently expressed concerns about the treaty's impact on the US missile defenses program in Europe.

However, the White House has issued a statement: "This landmark agreement advances the security of both nations, and reaffirms American and Russian leadership on behalf of nuclear security and global non-proliferation."