The UN has confirmed it has received documents from Syria on joining the Chemical Weapons Convention, which outlaws their production and use.
Syria's President Bashar al-Assad earlier told Russian TV the papers were being sent and that it would submit weapons data one month after signing.
US and Russian foreign ministers are preparing to meet in Geneva to discuss the plan, proposed by Moscow this week.
The US accuses the Syrian regime of killing hundreds in a chemical attack.
The government denies the allegation, blaming rebels for the attack in the Ghouta area of the capital, Damascus, on 21 August.
Russia announced its proposal for dealing with the escalating chemical weapons crisis on Monday, as the US Congress was preparing to debate whether to back President Barack Obama's moves towards military action against Syria.
'Chance for peace'
UN associate spokesman Farhan Haq said the Syrian documents were in the process of being translated.
The convention requires all parties to declare and destroy all of the chemical weapons they possess.
In his interview, which has not yet been broadcast in full, Mr Assad told state-run Rossiya 24: "Syria is placing its chemical weapons under international control because of Russia. The US threats did not influence the decision."
He confirmed that Syria was sending relevant documents to the UN as part of the process of signing the Chemical Weapons Convention.
Mr Assad said Syria would then submit information on its chemical weapons one month after signing.
He also said that Russia's proposal was "not unilateral", adding: "Syria will accept it if America stops military threats and if other countries supplying the rebels with chemical weapons also abide by the agreement."
He said only Russia could make the agreement happen as "Syria has neither contacts with, nor trust in, America".
Earlier on Thursday, Russian Foreign Minister Sergei Lavrov outlined three main phases of the proposal:
- Syria joins the Chemical Weapons Convention
- Syria reveals where its chemical weapons are stored and gives details of its programme
- Experts decide on the specific measures to be taken
Mr Lavrov - who is to meet US Secretary of State John Kerry in Geneva soon - said during a visit to Kazakhstan: "I am sure that there is a chance for peace in Syria. We cannot let it slip away."
He did not mention the destruction of the weapons, which was part of Moscow's original proposal but is thought to be a sticking point in negotiations with Damascus.
Before meeting Mr Lavrov, Mr Kerry has been holding talks with UN-Arab League envoy to Syria, Lakhdar Brahimi.
President Obama said on Thursday that he was "hopeful" of a positive outcome to the Kerry-Lavrov talks.
US officials had earlier described Russia's plan as "doable but difficult".
Officials travelling with Mr Kerry said they wanted a rapid agreement with the Russians on principles for the process, including a demand for Syria to give a quick, complete and public declaration of its stockpile.
The US postponed plans to launch military strikes on Syria after Russia proposed the disarmament.
Russian media have hailed the move as a diplomatic coup.
President Vladimir Putin affirmed this view by writing an opinion piece in the New York Times lambasting US policy, saying strikes would lead to an upsurge in terrorism.
But state department officials have been stressing the exploratory nature of the talks.
UK Foreign Secretary William Hague said the Russian plan "must be treated with great caution", and experts have pointed out the difficulty of conducting such a process in a war zone.
The main Syrian armed rebel group has already refused to co-operate.
Gen Salim Idriss of the Free Syrian Army said he categorically rejected the plan, and insisted that the most important thing was to punish the perpetrators of chemical attacks.
If the talks in Geneva are successful, the US hopes the disarmament process will be agreed in a UN Security Council resolution.
However, Russia regards as unacceptable any resolution backed by military force, or a resolution that blames the Syrian government for chemical attacks.
Moscow has already objected to a draft resolution that would be enforced by Chapter VII of the UN charter, which would in effect sanction the use of force if Syria failed in its obligations.
Russia, supported by China, has blocked three previous draft resolutions condemning the Assad government.
More than 100,000 people have died since the uprising against President Assad began in 2011.