THE HAGUE, Netherlands — The global chemical weapons watchdog on Wednesday urged Syria to intensify efforts to get its stockpile of raw materials for poison gas and nerve agents to a port, so it can be shipped out of the country and destroyed.

The first batch of toxic chemicals — believed to be precursors for mustard gas and sarin — was loaded onto a Danish cargo ship in the Syrian port of Latakia and shipped toward international waters on Tuesday, a week after the Dec. 31 deadline initially set for the chemicals to be removed from Syria.

Organization for the Prohibition of Chemical Weapons spokesman Michael Luhan said the Nobel Peace Prize-winning watchdog is "exhorting the Syrian government to intensify its efforts so we can conclude this critical part of this mission absolutely as fast as conditions allow."

Speaking at a closed-door meeting of the group's decision-making Executive Council, Director-General Ahmet Uzumcu said Syria has been given "virtually all of the necessary logistical resources for the ground transportation" of chemicals to Latakia, according to an OPCW statement.

The chemicals were supposed to have been removed from Syria by Dec. 31, but poor security, bad weather and other factors meant the deadline was missed.

The Danish ship is now in international waters waiting for the next consignment to arrive in Latakia.

The chemicals removed Tuesday will eventually be transferred to a U.S. ship, the Cape Ray, which has been fitted with special machinery. Once aboard the American vessel, the materials will be placed in a titanium reactor that uses heated water and other chemicals to render them inert.

The confirmed use of chemical weapons in the Damascus suburb of Ghouta on Aug. 21 killed hundreds of people, according to the U.S. government.

The United States and Russia — a staunch ally of Syria — later reached agreement to eliminate the Assad regime's chemical weapons by mid-2014 in a deal that averted U.S. military strikes against Syria.