No foreign power should be allowed to interfere in ongoing Syria peace talks in Geneva, its government negotiator said, as John Kerry landed in Russia seeking answers on plans for President Bashar al-Assad. 
Syrian envoy Bashar al-Jaafari denied high-level US-Russian meetings in Moscow will impact Syria's peace process in an interview with the AFP news agency on Wednesday.
"When we say that the dialogue must be between Syrians, without outside intervention, this also applies to the Russians and Americans," Jaafari said.
Jaafari, who serves as Syria's ambassador to the UN in New York, said believing that Moscow can pressure its ally in Damascus amounted to a "misreading" of the situation.
His comments came as US Secretary of State Kerry arrived in Moscow for a meeting with President Vladimir Putin and Foreign Minister Sergey Lavrov on Thursday.
Now that a fragile truce in Syria is in place and warring sides have begun peace talks in Geneva, Kerry wants to "get down to brass tacks" on the question of Assad, a US State Department official told Reuters news agency on condition of anonymity ahead of the meeting at the Kremlin. 
Russia has repeatedly said only the Syrian people can decide Assad's fate at the ballot box, and has bristled at any talk of removing the Syrian government. 
Negotiations in Geneva, entering a 10th day Wednesday, were rattled last week by Russia's surprise decision to withdraw most of its troops from Syria, a move analysts say could help peace efforts by weakening Assad's position.
The meetings in Moscow on Thursday are expected to touch on a fragile ceasefire declared on February 27, which has raised hopes for an end to the five-year Syrian conflict that has killed more than 250,000 people, and forced millions to flee their homes, according to the UN. 
The State Department official played down expectations the meetings would have an immediate impact on peace talks.
"Obviously what we are looking for - and what we have been looking for - is how we are going to transition Syria away from Assad's leadership," the official said.
Al Jazeera's Whitney Hurst, reporting from Geneva, said Jaafari gave a statement after meeting with UN Special Envoy for Syria Staffan de Mistura, in which he condemned the attacks in Brussels and described them as the result of failed counter-terrorism policies.
There has been no confirmation that the attackers in Brussels had fought in Syria, but the cell that carried out November'sParis attacks had fought with Islamic State of Iraq and the Levant (ISIL, also known as ISIS) in the country.
Syrians protest to mark the fifth anniversary of the war's start [EPA]