A growing number of House and Senate Republicans are warning that their support for President Barack Obama’s plan to increase troop numbers in Afghanistan is not guaranteed because of concerns about details in the proposal.

Obama is scheduled to unveil the Afghanistan strategy Tuesday night at the West Point military academy, and given the widespread opposition to a troop increase within the Democratic Party, Republican support could be critical.

But Republicans say that if the proposal contains a strong exit strategy or fails to provide a sufficient number of troops to the region, they may not support the administration’s approach.

Over the past few months, House and Senate Republicans have pushed Obama to release a plan for Afghanistan and have urged Obama to adopt Gen. Stanley McChrystal’s recommendation to deploy an additional 40,000 troops to secure the region.

House Republican Study Committee Chairman Tom Price (Ga.), one of the president’s most vocal critics, said members of the House Republican Conference would be listening carefully to the tone of Obama’s Tuesday night speech.

“I think that remains to be seen,— Price said, when asked about Republican support. “His speech could fall so flat on the ears of the American people. This president has to be committed— to the war.

Price, who met with McChrystal in Afghanistan last week, reiterated that Republicans would continue to support U.S. troops and their mission, but that support means providing them with the resources and the equipment they need to be effective.

He added that a firm exit timeline or a phased increase in the number of troops would be met with strong resistance from Congressional Republicans.

“Rolling people in 1,000 at a time is a political response,— Price said.

Josh Holly, a spokesman for House Armed Services ranking member Howard McKeon (R-Calif.), said Republicans would be looking for Obama to make a “spirited defense— of his strategy.

“At the end of the day, it is the responsibility of the commander in chief to rally the nation and the Congress around his strategy for success in Afghanistan,— Holly said.

In an interview on “Fox News Sunday,— Senate Minority Whip Jon Kyl (R-Ariz.) also cautioned against a phased increase, saying a proposal for a gradual escalation would be “reminiscent of Vietnam.—

Senate Republican Conference Chairman Lamar Alexander (Tenn.) said in a statement Monday that he hopes Obama will “come before Congress and tell us exactly what the United States should try to accomplish in Afghanistan and why — outline a success strategy, not an exit strategy,— Alexander said. “Ask for the country’s bipartisan support in completing that mission all the way through to the end.—

Rep. Jason Chaffetz (R-Utah) said Monday that there was little Obama could say to persuade him to continue supporting the war, which he said had devolved into a nation-building effort.

“Republican support is not guaranteed,— Chaffetz said. “A lot of conservatives are opposed to the idea of nation-building.—

Chaffetz argued that with the emerging threat of a nuclear Iran and the rising national debt, he could not justify making Afghanistan a top priority.

One House GOP aide predicted Republicans would end up supporting Obama’s strategy even if they believe more needs to be done to win the war in Afghanistan. But the aide said Republicans would make sure to distance themselves from parts of the policy in which they disagree with the president.

Rep. Kay Granger (R-Texas), who also met with McChrystal in Afghanistan last week, said it was unlikely that Republicans would vote against Obama’s strategy.

Granger said McChrystal urged Members of Congress and the American people to be patient with the efforts in Afghanistan.

“He was very adamant about creating a time and space for the Afghan [military] to become trained and capable of taking care— of their country, Granger said. “To accomplish that he needs more personnel — more troops.—