The Syrian government is working constructively with the international team charged with overseeing the destruction of the nation's chemical weapons, the chief of the world's chemical weapons watchdog said Wednesday.

Inspectors visited a first site earlier this week, where they saw some chemical weapons equipment already destroyed, and are expected to visit more than 20 others over the coming days, said Ahmet Uzumcu, director-general of the Organization for the Prohibition of Chemical Weapons.

"The cooperation has been quite constructive, and I will say that the Syrian authorities have been cooperative," Uzumcu told reporters at The Hague Wednesday.

Syria has until mid-2014 to destroy its chemical weapons or face consequences, according to the U.N. Security Council resolution that authorized the joint OPCW-U.N. mission. The mission comes amid Syria's civil war -- a conflict that will make the inspectors' movements and work difficult.

The international weapons inspectors must complete their initial inspections of all Syrian chemical weapons and storage facilities by November 1 and complete the eradication of production and chemical mixing facilities, the resolution says.

Syria must submit a plan for destroying the weapons by October 27, Uzumcu said. Inspectors will visit a second site Wednesday, he said.

The time line is tight and the inspectors face significant challenges, including having to cross front lines and move through areas controlled by militants fighting Syria's government. Uzumcu hinted that if the deadlines are to be met, cooperation from rebels would be key.

"I think the elimination of those weapons is in the interest of all. Therefore, if we can assure some cooperation by all parties and if some temporary cease-fires could be established in order to permit our experts to work in a permissive environment, I think our targets could be reached," he said.

Still, it will be up to the Syrian government and the United Nations to make sure that inspectors can get to the rebel-held areas, OPCW official Malik Ellahi said Wednesday.

Missile warheads, mixing equipment destroyed this week

The U.N. resolution, which capped a month of dramatic diplomacy, was based on a deal struck between the United States and Russia that averted an American military strike over allegations the Syrian government used sarin nerve gas in an August 21 attack on a Damascus suburb.

U.S. officials said at least 1,400 people died in the attack. Syria denied responsibility, blaming rebel forces.

More than 100,000 Syrians have been killed in the country's civil war since an uprising began in early 2011, according to the United Nations.

Syrians began destroying their country's chemical weapons program Sunday under the oversight of the advance OPCW-U.N. team, U.N. Secretary-General Ban Ki-moon said in a letter to the U.N. Security Council on Monday.

Syrian personnel used "cutting torches and angle grinders to destroy or disable a range of items," the OPCW said. "This included missile warheads, aerial bombs and mixing and filling equipment."

Over the period of eight months, inspectors are expected to "support, monitor and verify the destruction of a complex chemical weapons program involving multiple sites spread over a country engulfed in violent conflict."

This includes about 1,000 metric tons of "chemical weapons, agents and precursors that are dangerous to handle, dangerous to transport and dangerous to destroy," Ban said.

The time frame would be ambitious in the most peaceful of circumstances, he said, but the current conditions make it "an operation the likes of which, quite simply, have never been tried before."

Syria made a declaration of its chemical weapons sites in September. Speaking about Syria's initial cooperation, Uzumcu said Wednesday that the government has appointed an ambassador and technical experts to work with the inspectors.

There has been some skepticism over whether Syria will give up its entire chemical weapons arsenal.

A defected Syrian brigadier general, Zaher al-Sakat, told CNN's Christiane Amanpour last week that in addition to four secret locations within Syria, the regime is currently transferring chemical weapons to Iraq and Lebanon, an allegation that the commander of the opposition Free Syrian Army, Gen. Salim Idriss, also recently made to Amanpour. Iraq and Lebanon have denied the claims.

2 more French journalists held in Syria

Two more French journalists are being held after they were kidnapped in war-torn Syria, adding to two others whose abductions were reported this year, the French Foreign Ministry said Wednesday.

Reporter Nicolas Henin and freelance photographer Pierre Torres have been held since June 22, but their kidnappings were kept confidential at the request of their families, the ministry said.

The two other French journalists, reporter Didier Francois and photographer Edouard Elias, have been held in Syria since June 6, the ministry said.

The ministry has not said who is holding the journalists. It said "all means of the state are mobilized" to free them.

Henin was preparing a report for the Le Point news magazine and the Arte media chain, and Torres had been expected to cover municipal elections organized for Raqqah, Syria, he ministry said.

Francois and Elias, working for French radio station Europe1, had been on their way to the northwestern city of Aleppo when they were captured, the station has said.

CNN's Stephanie Halasz, Joseph Netto, Laura Smith-Spark and Joe Sterling contributed to this report.