President Bush will tell the nation Wednesday night that a gradual "surge of 20,000 U.S. troops" to Iraq will begin later this month, and that the administration expects the government of Prime Minister Nouri al-Maliki to seize control of all 18 provinces by November, senior U.S. officials confirmed to FOX News.

Roughly half of the troop surge would be sent to Baghdad, which has been consumed by sectarian violence, while another 4,000 would head to the western Anbar Province, a base of the mostly Sunni insurgency and foreign Al Qaeda fighters, Sen. Kay Bailey Hutchison, R-Texas, and others said following a White House session with Bush.

Officials stressed, however, that the timing of the troop deployment ultimately is up to Gen. George Casey, the top U.S. commander in Iraq.

It is widely expected that the first wave of the build-up will be comprised of the 2nd Brigade of the 82nd Airborne Division, which arrived in Kuwait earlier this week.

About 132,000 U.S. troops currently are in Iraq. Much of the expected increase would come from speeding up the timetable for some forces already scheduled to deploy, and keeping others there who were about to leave.

In his plan to be announced to the nation at 9 p.m. EST Wednesday, Bush also is expected to place political benchmarks on the Iraqi government in an effort to stem sectarian violence that is tearing apart the country. Provisions include curbing Shiite militias that have terrorized the Sunni minority, enacting a plan to distribute oil revenue to the country's sects and easing government restrictions on members of former Iraqi leader Saddam Hussein's Baath Party. The speech will include a call for Iraqis to have control of all 18 Iraqi provinces by November 2007.

The White House has been trying to close the sale of a troop build-up behind closed doors, meeting privately with lawmakers. But with division among Democrats and Republicans about the plan, the White House also realizes the president must appeal to the American people. They will be the target of Wednesday's speech, said White House Press Secretary Tony Snow.

"As far as public opinion, the president will not shape a policy according to public opinion, but he does understand that it's important to bring the public back to this war and restore public confidence in support for the mission," Snow said.

Opponents on Capitol Hill have not been shy about their opposition. In a speech in Washington, Sen. Edward Kennedy outlined his objections to be put in the form of a bill that would cut money from troop "escalation."

"Our bill will say that no additional troops can be sent and no additional dollars can be spent on such an escalation unless and until Congress approves the president's plan. Our proposal is a straightforward exercise of the power granted to Congress by Article I, Section 8 of the Constitution," Kennedy, D-Mass., said.

Senate Majority Leader Harry Reid also told reporters that he has asked committee chairmen Joe Biden of the Senate Foreign Relations Committee and Carl Levin of the Senate Armed Services panel, along with Sen. Jack Reed, an Army veteran, to craft a new Senate Democratic resolution on Iraq to be introduced once the president has spoken.

Reid said it would be a bipartisan statement voicing opposition to the president's expected call for a troop surge. Reid noted nine Republicans have announced opposition. Sen. Dick Durbin, D-Ill., said the resolution will be a "sense of the Senate," which does not have the force of law, but will be more than a revision of last year's Levin-Reed amendment calling for a beginning of troop redeployment from Iraq.

Levin, D-Mich., said he expects Bush to announce up to 20,000 additional troops to Iraq but not say how long the extra forces will be there. Levin, who spoke to reporters a day after meeting with White House national security adviser Stephen Hadley, said he believes Bush will signal that the overall U.S. commitment in Iraq is not open-ended.

FOX News' Nick Simeone and Trish Turner and The Associated Press contributed to this report.