HOUSTON --The U.S. Marshal's Office say they are "aggressively pursuing" the Jessica Tata case. However, an agency spokesman adds that it is doing so through diplomatic channels by letting the Nigerian government know that U.S. law enforcement wants Tata back on American soil. Tata has been a wanted fugitive since last month when a fire at her west Houston daycare killed four children and injured three others. An indictment alleges she left the children alone while she went shopping. Tata has been elevated to the top 15 most wanted fugivites by U.S. Marshals but it's doubtful she is on U.S. soil. Authorities say she is subject to an international search, but as to the intensity of this search, there seem to be mixed messages. The question is who's trying to find her? Congresswoman Sheila Jackson Lee says she's spoken to the ambassador to Nigeria. "I've asked him to convey to the president and national security advisor a request that Nigerian law enforcement officials be utilized in this effort to be able to help us find Ms. Tata," Jackson Lee said on Sunday. And at a vigil for the children who died, the regional Nigerian consul general -- an invited guest -- had guarded remarks. "And I express my willingness to come to Houston to have a meeting with her, and they said, 'Oh something, something of this nature happened' and that's all," said Baba Garba with the Nigerian Consul General of Atlanta. "But officially, I've not been informed of anything that has taken place." This statement today from the State Department: "The Embassy and Department or State are very aware of the case and have been taking appropriate steps in Nigeria in close coordination with Harris County authorities and the U.S. Marshals Service. As this is an ongoing case, we can't provide details about what steps are being taken." Eyewitness News Anchor Art Rascon was in Nigeria last week and did not get a sense of urgency from Nigerian authorities, some telling him they hadn't heard of Tata. On his trip this past week to Nigeria, Eyewitness News reporter Art Rascon found no evidence of any active search by Nigerian authorities nor anyone else. Our legal analyst Joel Androphy, who's been a witness to several foreign extradition fights, says it may take years to get Tata back. Finding her in a country larger than Texas he says is one hurdle. Getting a foreign government to detain someone and then agree to turn that person over to the U.S. is the second hurdle. He believes it will take years to get her back. A $25,000 reward is being offered by the U.S. Marshal's Office for information leading to Tata's arrest.