TOKYO, August 30 (RIA Novosti) - Russian-U.S. talks on a replacement for the START-I arms reduction treaty will be held in early September in Rome, a high-ranking Russian Foreign Ministry disarmament official said Thursday.

"It's difficult to say yet what it will deliver. Talks are ongoing. We would like this to be a legally binding agreement which demonstrates our countries' commitment to nuclear disarmament, strengthening the predictability in our relationship and to reflect all the best and most efficient things that are in the current START treaty," Anatoly Antonov said on a visit to Japan.

The START-I Treaty was signed July 31, 1991 and expires December 5, 2009.

It remains in force as a treaty between the U.S., Russia, Belarus, Kazakhstan, and Ukraine. Belarus, Kazakhstan and Ukraine have since totally disarmed their strategic arms capabilities, and the U.S. and Russia has reduced the number of delivery vehicles to about 1,600, with no more than 6,000 warheads each.

The treaty was followed by START-II, which banned the use of multiple re-entry vehicles (MIRV), but never came into force and was later bypassed by the Strategic Offensive Reductions Treaty (SORT), signed by Vladimir Putin and George W. Bush in Moscow May 24, 2002, also known as "the Moscow Treaty."

U.S. senator Richard Lugar said Tuesday Russia and the U.S. should extend the START-I treaty, or it could result in negative consequences.

"The United States and Russia must extend the START Treaty's verification and transparency elements, which will expire in 2009," Lugar told an arms control round table in Moscow.

Lugar said the two countries should also introduce additional verification elements for the SORT treaty.