WARSAW. The United States has called on Syria to take immediate action to comply with a UN resolution to remove its chemical weapons materials, noting just four percent of Syria’s declared chemical stock has been eliminated.Efforts to remove these materials from Syria have "seriously languished and stalled,” US Ambassador Robert Mikulak said in a statement to the Organisation for the Prohibition of Chemical Weapons (OPCW) on Thursday."Syria must immediately take the necessary actions to comply with its obligations under the Chemical Weapons Convention, Executive Council decisions, and UN Security Council Resolution 2118,” said Mikulak, the US permanent representative to the OPCW.Timelines adopted last year required that 100 percent of "priority one” chemicals be eliminated by December 31, 2013, while the deadline for removing "priority two” chemicals is Feburary 5. That deadline will also not be met.The Syrian government has attributed the delays to "security concerns,” saying it needs additional equipment to ensure their safe transportation - a claim Mikulak rejected."Syria’s requests for equipment and open-ended delaying of the removal operation could ultimately jeopardise the carefully timed and coordinated multi-state removal and destruction effort,” he said.During a visit to Poland on Thursday, US Defence Secretary Chuck Hagel also criticised Syrian efforts, saying he has asked his Russian counterpart to put pressure on Damascus to comply with the deal."I do not know what the Syrian government’s motives are - if this is incompetence - or why they are behind in delivering these materials,” Hagel told reporters in Warsaw, the capital. "They need to fix this.”Peace talks continueMeanwhile, peace talks between the Syrian government and the opposition continued on Thursday, with UN mediator Lakhdar Brahimi reporting little progress.In an afternoon update to the media in Geneva, Switzerland, Brahimi said he hoped the two sides would "draw some lessons” from the first round of talks, scheduled to end today, in hopes of becoming better organised for the next round.Terrorism was among the topics discussed on Thursday, Brahimi said, although there was no agreement on how to deal with it."We had tense moments and also rather promising moments,” he said.Opposition delegation spokesman Louay Safi told reporters that the two sides had spoken about stopping the violence in Syria, noting the opposition presented evidence of government massacres within residential neighbourhoods.Safi said the government wanted to speak first about issues such as ending the violence and bringing humanitarian aid, instead of dealing with the trickier issue of a political transition. "We believe this is the wrong sequence,” he added.The opposition views a transitional government as the first step towards a political solution, and has insisted that President Bashar al-Assad step down.The Geneva 1 communique, a never-implemented roadmap developed during 2012 talks, calls for a transitional government, but the regime denies the document requires Assad to resign.