By Khaled Yacoub Oweis DAMASCUS, Feb 9 (Reuters) - Syria has assured the United Nations it would keep hosting one million Iraqi refugees despite new rules imposed on residency, the U.N. High Commissioner for refugees said on Friday. Antonio Guterres told journalist in Damascus that measures requiring Iraqis to quickly apply for residency imposed a few weeks ago were motivated by security concerns and do not represent a change in government policy on hosting refugees. "There was a clear statement from the government members I met that no Iraqis will be sent back to Iraq against their will in the present dramatic circumstances," Guterres said after meeting senior Syrian officials. "Syria's policy of hosting Iraqi refugees will be maintained," he told a news conference. Under the new regulations, Iraqis will be required to fill out an entry form upon arrival in Syria, and apply for residency within 15 days instead of three month. Syrian authorities also insist that Iraqis living in the country without residency must obtain one. Iraqi politicians have strongly criticised the new measures, saying they would severely limit the options of Iraqis fleeing violence. Jordan, another destination for Iraqi refugees, has imposed severe restrictions on their entry. Ties between Syria and the U.S.-backed Iraqi government, long soured by allegations of Syrian support for anti-US rebels, remain tense despite restoration of diplomatic ties in December. Iraqi refugees say Syrian authorities have been deporting Iraqis accused of fomenting sectarian tensions at home. The U.N. High Commissioner for Refugees estimates that up to 2 million Iraqis have moved to neighbouring countries, mainly Syria and Jordan, before and since 2003 U.S.-led invasion of Iraq, while 1.7 million are internally displaced. Thousands more continue to cross daily into Syria, a country of 18 million people, across the porous desert border with Iraq. Syria, already home to 432,000 Palestinian refugees, has been the most welcoming host for Iraqis, despite the extra burdens they create on the economy. Syrian officials say the new measures were taken to keep track of the thousands of new refugees who continue to pour across the porous borders, further straining the country's infrastructure and driving property and rental prices up. Guterres said he understood Syria's security worries. "There is a concern by the Syrian authorities about the security of the country. It is understandable," Guterres said. The High Commissioner is on a week-long trip to the Middle East to marshal funds for the agency's $60 million appeal and to mobilise international support to help host countries.