MOSCOW - U.N. Secretary-General Kofi Annan voiced hope Tuesday that Russia, China and other international mediators would help ease mounting tension between India and Pakistan and prevent their conflict from going nuclear.

"I hope none of us will contemplate a nuclear war," Annan said.

As Annan spoke in Moscow, Pakistan's President Pervez Musharraf refused to renounce first use of nuclear weapons - a statement that further jacked up tension.

"The possession of nuclear weapons by any state obviously implies they will be used under some circumstances," Musharraf said Tuesday during an Asian security summit in Almaty, Kazakhstan, that he and Indian Prime Minister Atal Bihari Vajpayee both attended.

Annan said, "I'm working very closely with other world leaders to try and help de-escalate the situation," adding he expected the mediation efforts by Russian President Vladimir Putin and Chinese President Jiang Zemin to "help reduce tensions and save us from any further escalation."

Russia and China pressed India and Pakistan to enter face-to-face talks to prevent the clashes in Kashmir from exploding into a full-fledged war between the nuclear-armed neighbors. Their mediation efforts failed to bring Musharraf and Vajpayee together for a direct meeting in Almaty, but Musharraf said he had accepted Putin's invitation for possible talks in Moscow.

Annan also said he remained in contact with both Vajpayee and Musharraf. "I've spoken to them as recently as yesterday," Annan said.

The speaker of Russia's upper house of parliament, Sergei Mironov, said he and Annan also discussed the Mideast conflict, the situation in Afghanistan and the Iraqi crisis along with conflicts in the former Soviet republics, including Georgia and Azerbaijan.

Annan is expected to meet with Putin and other Russian leaders during his three-day visit to Russia.