Obama to call Medvedev to finalize arms treaty

US President Barack Obama will call his Russian counterpart Dmitri Medvedev Friday to finalize a new nuclear arms reduction agreement, the White House said.

The call will take place at 10:00 am (0200 GMT) ahead of an announcement that the two sides have reached an agreement for a successor to the landmark Strategic Arms Reduction Treaty (START) that expired in December.

US Secretary of State Hillary Clinton, Defense Secretary Robert Gates and Chairman of the Joint Chiefs of Staff Admiral Mike Mullen were scheduled to brief reporters at 10:45 am, the White House said.

"We are, I think, very close to having an agreement on a START treaty but won't have one until President Obama and his counterpart, Mr Medvedev, have a chance to speak again," White House spokesman Robert Gibbs said on Wednesday.

Czech TV Nova said both sides would sign the new treaty on April 8 in Prague, where Obama gave a major speech last April calling for a world free of nuclear weapons while acknowledging he may not live to see that goal achieved.

Obama and Medvedev set a goal in July of slashing the number of warheads on either side to between 1,500 and 1,675 warheads and the number of "carriers" capable of delivering them to between 500 and 1,100.

The United States has said it currently has some 2,200 nuclear warheads, while Russia is believed to have about 3,000.

Moscow and Washington have held months of difficult negotiations aimed at replacing the treaty, a cornerstone of Cold War-era strategic arms control.

Signed in 1991, START led to huge reductions in the Russian and US nuclear arsenals and imposed verification measures to build trust between the two former Cold War foes.

Delays in the START talks and missed deadlines have cast a shadow over the Russian and US leaders' efforts to make good on their pledge to improve bilateral ties.

The United States is set to host a nuclear security summit on April 12-13, and observers have said it is a matter of pride for Washington to have the new treaty in place before the summit. A review conference for the Nuclear Non-Proliferation Treaty (NPT) is scheduled for May.

Analysts said US Republicans who staunchly back missile defense may try to deny the Obama administration the two-thirds majority it needs in the Senate to ratify the START treaty.