UPATE 1-US growing but must shelter recovery - White House

* US entering 2011 with momentum -White House

* Recovery still fragile, must be encouraged

* Obama spending freeze part of deficit balancing act (Updates with Goolsbee on fiscal policy)

WASHINGTON, Jan 27 (Reuters) - President Barack Obama's top economic adviser said on Thursday U.S. growth still needs stimulus from fiscal policy as it gathers speed but has entered 2011 on a strong note.

"We've got some momentum. We're going into 2011 with some growth," White House Council of Economic Advisers Chairman Austan Goolsbee told a question and answer session on YouTube.

The daylong event, which climaxes with an appearance by the president, follows up on Obama's State of the Union address to the nation on Tuesday.

Goolsbee said a five-year spending freeze announced during the speech was aimed at longer-term deficit goals and would not jeopardize the recovery.

"The spending freeze on discretionary non-security (spending) that the president outlined is over the next five years. It is not designed to go yank the rug out from under the recovery right now," he said.

The non-partisan Congressional Budget Office forecasts the U.S. deficit will hit $1.48 trillion this year, and the International Monetary Fund warned the country must tackle its fiscal challenges before investors lose patience.

But Goolsbee said the increase in the budget deficit was caused by temporary factors beyond the control of the Obama administration.

"The reason the deficit is large last year and this year is not from the long run fiscal challenges facing the country, it's because we just went through the worst recession in virtually all of our lifetimes," he said.

"As you look out over the next five years we've got to obviously make tough choices to keep the fiscal situation from deteriorating. So it is a bit of a balancing act," he said.

(Reporting by Matt Spetalnick and Alister Bull; Editing by Doina Chiacu)