Time is running out to save Haitians buried under the rubble left in the wake of the massive earthquake that struck the country last week, dpa quoted a senior US official as saying. Tim Callahan, the US Agency for International Development's head of the disaster response teams on the ground in Haiti, said they will continue working to rescue trapped victims for the next couple days but cautioned that the chances of finding people alive are diminishing. "We're getting closer to getting to where you would go from rescue to recovery," he told reporters in a conference call from Port-au- Prince. He said US teams have rescued 39 people from the ruins and 71 others have been saved by teams from other countries. The Haitian capital was destroyed by the magnitude-7.0 earthquake on Tuesday. Authorities free up to 200,000 could have perished. The United States has launched a massive operation to provide food, water and other needs to the Caribbean nation of 9 million people. There are 1,700 US soldiers already on the ground, with that number expected to reach 5,000 by the middle of the week. A fleet of Marines on amphibious ships are expected to arrive by Tuesday, bringing the total US presence in the vicinity to 10,000 soldiers along with support personnel, the military said. The US contingency will assist with security while running operations to distribute humanitarian supplies. There have been reports of sporadic violence as Haitians rush to get their hands on goods, but overall the situation remains relatively calm, said Rear Admiral Mike Rogers, the director of intelligence on the Pentagon's Joint Chiefs of Staff. The security environment allowed for the US military to run its full scope of operations to distribute supplies, and "we have seen nothing" that suggests widespread disorder.