WASHINGTON — As Rhode Island’s congressional delegation spoke out last night against President Bush’s plan to put 20,000 more troops in Iraq, Rep. Patrick J. Kennedy announced that he will support a bill to require congressional approval for any additional deployment of U.S. forces.

Twenty thousand troops is a drop in the bucket in terms of what’s needed to control the situation in Iraq, Kennedy said, “but it’s too many Americans to put in harm’s way.”

Rep. James R. Langevin, another member of the all-Democratic delegation, said that if it is constitutional, he too may vote to mandate congressional approval for any increase of the U.S. force in Iraq, which currently stands at 132,000, and of new costs associated with Mr. Bush’s plan.

Sen. Edward M. Kennedy and Rep. Edward J. Markey, both Massachusetts Democrats, have proposed such legislation, which would mark a significant congressional step toward forcing change in the Iraq policy.

Sen. Jack Reed indicated that he prefers a non-binding Senate resolution of disapproval of the troop increase, which Democratic leaders have said they will introduce.

Reed has said in the past that he might support troop increases in Iraq if military leadership deemed it necessary. But last night, he said he is opposed to the plan Mr. Bush unveiled because he believes there is significant military skepticism and opposition to it. Reed also said that Mr. Bush’s troop increase will be too small and gradual to have much effect.

Sen. Sheldon Whitehouse said he will study whatever legislation is proposed in response to Mr. Bush’s plan. But he said he would not take “off the table” a possible vote for Sen. Kennedy’s bill.

Whitehouse said Mr. Bush’s new plan is “not a change in course at all but rather a leap further down the same road that we’ve been on.”

“An escalation of the war in Iraq is a misguided response to a failed strategy,” Rep. Kennedy said in a statement issued before the speech. He said Iraq’s “political problem and civil war” cannot be solved by putting more U.S. troops “between the warring parties.”

Kennedy dismissed any suggestion that a vote blocking the deployment of additional troops to Iraq could be seen as a withdrawal of support for the U.S. troops in Iraq.

Langevin said before the president’s speech last night that it must be made clear to the Iraqi government “that we do not plan to be in Iraq indefinitely and they must step in soon to secure their own security” — a point Mr. Bush made publicly for the first time last night.

The four legislators all repeated their view that the U.S. military should focus on training and support of Iraqi forces as a step toward U.S. force reductions.

All four Rhode Islanders said the president’s planned troop increase will do little to improve the situation in Iraq.

Langevin called Mr. Bush’s speech “just more of the same. The president just does not get the messages that this is a failed policy in Iraq and he needs to change course.”

As details of Mr. Bush’s plan emerged before the speech, Reed said that the planned troop increase is too marginal to affect change.

Reed also said that the administration has yet to tackle the fundamental need to prod Iraq’s government toward political reform and public works spending that might build the kind of popular support that could bring stability.

Reed said, further, that the troop increase is problematical because it will be accomplished by extending deployments of troops already in the region. Reed said that will further tax the armed forces that are already stretched thin.

Last night Reed, Whitehouse and Kennedy all welcomed Mr. Bush’s first public embrace of suggestions that Reed has made for months, including a call upon Iraq’s government to hold regional provincial elections to spread political representation to all parties, and to begin spending the government’s $10 billion in oil monies on public works.

Reed said, however, that Mr. Bush may not have the leverage to turn those suggestions into action.