"It was with mixed emotions that I informed President Barack Obama and Secretary Kerry that I will step down as Administrator in mid-February 2015," Shah said in a statement.
Thanking Shah, who headed USAID for more than five years, President Obama said in a statement: "Shah has been at the center of my administration's efforts to advance our global development agenda as the administrator of USAID."
"To be sure, his tasks have never been easy -- responding to natural disasters, epidemics, and famine, to name just a few examples," he said.
"But Shah, the son of proud Indian immigrants, has embodied America's finest values by pro-actively advancing our development priorities, including ending global poverty, championing food security, promoting health and nutrition, expanding access to energy sources, and supporting political and economic reform in closed societies," Obama said.
Joining Obama in praising Shah, Kerry said:
"After five years, he absolutely deserves this transition, and he leaves USAID after making a dramatic mark -- transforming this institution into one that's more entrepreneurial, more modern, and more nimble, while promoting resilient democracies and battling extreme poverty across the globe," he said.
"Raj will be known not just as USAID's 16th Administrator, but as the Administrator who reached up, and reached out, bringing a whole new set of stakeholders to the table," Kerry said.
In a statement, Shah said Obama's call to end extreme poverty -- made in two State of the Union addresses -- re-energized USAID and elevated its work in the national security agenda.
"In the years since, we have seized upon this challenge, advancing a new model of development that harnesses the power of business and innovation to achieve this goal.
"With this new model, we have delivered meaningful results -- from fighting hunger, to educating girls, to tackling climate change, to fighting for civil society and democratic values," he said.
"We are better positioned than at any other time in our 53-year history to solve the greatest challenges facing humanity," he said.
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