(Adds additional comments from U.S. defense secretary, White House spokesman)
By Missy Ryan
WARSAW, Jan 30 (Reuters) - The United States is concerned that the Syrian government is behind schedule in removing chemical weapons materials due to be destroyed, U.S. Defense Secretary Chuck Hagel said on Thursday, calling on Syria to comply with an international disarmament deal.
"The United States is concerned that the Syrian government is behind in delivering these chemical weapons precursor materials on time with the schedule that was agreed to," Hagel told reporters during a visit to Poland.
Hagel said he discussed the issue in a call on Wednesday with his Russian counterpart, Defense Minister Sergei Shoigu, and asked him to "do what he could to influence the Syrian government to comply with the agreement that has been made" for destroying the chemical weapons.
Last year's chemical weapons deal appeared to provide Syria a last-minute reprieve from possible Western military action that would have been launched in response to a major chemical attack last August.
But sources have said that Syria has given up less than 5 percent of its chemical weapons arsenal ahead of a Feb. 5 deadline in the disarmament process.
The White House said Syrian needs to intensify its efforts to transport chemical weapons to the port of Latakia.
"It is the Assad regime's responsibility to transport those chemicals to facilitate removal. We expect them to meet their obligation to do so," White House spokesman Jay Carney told reporters traveling aboard Air Force One.
Hagel said the U.S. ship Cape Ray, which was specially equipped to dispose of Syria's chemical weapons at sea, left a U.S. port earlier this week.
"We believe that this effort can continue to get back on track even though we're behind schedule, but the Syrian government has to take responsibility for fulfilling its commitment that has been made," Hagel said. (Additional reporting by Jeff Mason aboard Air Force One; Editing by Chizu Nomiyama and Tom Brown)