( CNN ) -- Peru 's president arrived Tuesday night at a mine in southern Peru , where he was expected to lead an operation to reach nine trapped miners . `` We have been able to talk with the miners . Their spirits are quite high , '' President Ollanta Humala told reporters outside the mine . But more work needs to be done before the rescue begins , Humala said . Engineers were working to make sure the mine was secure `` so there are no victims , '' he said . `` Those same engineers tell us that we have to wait a few hours . They have n't said how many , '' the president said . The miners have been stuck since Thursday in the wildcat Cabeza de Negro mine in southern Peru . Earlier Tuesday , one of the mining engineers in charge of the rescue declined to give a specific time frame for the operation . `` We ca n't say how long it will take right now to get them out , but I can guarantee that they are alive , that they are in good health , and that ultimately they are going to be freed alive , '' engineer Carlos Bejarano said . A cave-in over the weekend complicated efforts . `` It 's very complicated work . We 're taking into account all the necessary security measures to avoid risks among the rescuers themselves , '' said Cesar Chonate , a regional head of Peru 's civil defense agency , the state-run Andina news agency reported . Video from state-run TV Peru showed workers , wearing hard hats and headlamps , loading rocks into a pushcart by hand . It was not clear what caused the initial collapse . The miners have been getting oxygen , food and water through a tube , which has also allowed them to stay in contact with people above ground , Andina reported . Peruvian Mining Minister Jorge Merino was also in the area and appealed to mining companies for their expertise , according to a statement from his office . Mining is big business in Peru , which is a major world producer of copper , silver , gold and other minerals . `` The important thing is that the nine people are alive . We wo n't abandon them , '' Merino said . The ordeal stirred memories of a 2010 Chilean mine collapse in which 33 men were trapped underground for 69 days . All those miners were rescued , pulled one by one from hundreds of meters beneath the Earth 's surface with a specially designed capsule .
NEW : Peru 's president says it will be `` a few hours '' before the rescue begins . NEW : The miners ' `` spirits are quite high , '' President Ollanta Humala says . Nine miners have been trapped since Thursday . In 2010 , 33 miners were rescued after being trapped underground for 69 days in Chile .