Are you a W-2 employee of the agency? Then no. Travel stipends are taxed and travel expenses are not deductible, that's part of the 2017 tax reform law.
If you are self-employed and will report your income and expenses on schedule C, then your travel expenses may be deductible, depending on several factors (mainly, how long was the assignment, and whether or not you have a "tax home" that is different from where you were working). See IRS publication 463, chapter 1. https://www.irs.gov/forms-pubs/about-publication-463
