LONDON, Feb. 21 -- Prime Minister Tony Blair announced Wednesday that 1,600 British troops would return home from Iraq in the coming months and that a further 500 soldiers may be withdrawn by the end of summer.

Even though Britain has only 7,100 troops in Iraq, compared with the 135,000-strong U.S. contingent, they carry symbolic importance as the largest allied presence. British forces make up half of the roughly 14,000 non-U.S. troops in the coalition in Iraq.

Vice President Cheney, in an interview with ABC News during a visit to Tokyo, called the planned withdrawal "an affirmation that there are parts of Iraq where things are going pretty well." Democratic leaders noted, however, that the British are withdrawing as President Bush is sending an additional 21,500 U.S. troops to Iraq.

Iraqi leaders generally welcomed the withdrawal plan, although Sunni officials said they feared the departure of British troops from Shiite-dominated southern Iraq would lead to increased sectarian violence that Iraqi security forces would be unable to stop.

Blair's plans allow him in the final months of his administration to show a measure of independence from Washington on Iraq policy. Battered in public opinion polls because of his support of the war, Blair has said he will step down by September.

At the same time Blair was speaking in London, the Danish prime minister, Anders Fogh Rasmussen, announced in Denmark that its 460 troops under British command in Iraq will return home by August. In Lithuania, a Defense Ministry spokeswoman said the country is "seriously considering" withdrawing its 53 troops from Iraq in August.

Blair said the British reduction in troops was possible because security conditions were better in southern Iraq, where British troops patrol, than in Baghdad, where many U.S. troops are located. He said that "80 to 90 percent of the violence" is in Baghdad, which is enduring an "orgy of terrorism."

British troops just completed an operation to turn over control of security to Iraqi forces in the southern city of Basra, Blair said. "What all of this means is not that Basra is how we want it to be. But it does mean that the next chapter in Basra's history can be written by Iraqis," he said.

But military and political analysts disputed Blair's upbeat description of the situation in the Basra area. They also said they believed the timing of the British drawdown may have more to do with plunging polls for Blair's Labor Party, pressure from British military officials and Blair's desire to begin an endgame for Iraq before he leaves office.

A poll this week showed that only 29 percent of respondents would vote for Labor, while 42 percent favored the opposition Conservative Party, the worst showing by Labor since 1992.

British military leaders are increasingly complaining of overstretched forces and low morale, and there has been growing military pressure on Blair to reduce the presence, said Michael Williams, head of the transatlantic program at the Royal United Services Institute for Defense and Security Studies.

"While the British zone is much quieter," he said, the Basra area "still has a number of security issues" and it "is foolhardy" to believe that Iraqi forces are ready to assume total control of the area. He also noted that if Blair had the political will, he could deploy some troops to help out the Americans in Baghdad instead of sending them home.

Coalition troops have handed over security control to the Iraqis in three southern provinces: Najaf, Muthanna and Dhi Qar. The 15 other provinces are still under the control of U.S.-led forces. American military officials have said they expect the Iraqis to take operational control of all Iraqi army divisions by this summer and to take security control in all provinces by fall.

"The Iraqi government feels very comfortable about the southern provinces and especially Basra; we have good security forces there," said Sami al-Askari, an adviser to the Shiite-led government of Prime Minister Nouri al-Maliki. Askari said he expects that after two months, the British troops will have moved out of the city center, restricting themselves to their bases, and that by the end of August 2008 there will be a full withdrawal of British troops.

"Now, the Iraqi security forces are not prepared. There will be a big security gap" when the British leave, said Naseer al-Ani, a Sunni member of parliament.

Ani and other Iraqi politicians saw the general trend of departing Western troops, whom they consider occupiers, as beneficial in the long term.

"Originally, the British forces, the American forces were coming to solve the situation and then they will leave. But we've seen the opposite: Wherever they stay for a long time . . . the situation keeps getting worse and worse," he said.

Iraqi forces in some cases have relied on coalition troops to bail them out in areas under their responsibility. In late January, a month after Iraqis took control of Najaf province, the Iraqi army needed the help of U.S. air support and ground troops to defeat an armed Shiite cult.

Still, officials in Najaf, which has a population of about 1.4 million people, said the departure of U.S. troops has been a political benefit.

"When the multinational forces were in Najaf, we had a lot of legal violations," said Najaf's governor, Asad Sultan Abu Gillel. Military operations were "carried out without legal notification, without an order from a judge," he said.

"This caused many problems for us with the local people," Abu Gillel said. "We live in a country filled with problems and terrorism, but at least we have full control."

At top strength, Britain had 40,000 troops in Iraq during the 2003 invasion. As of Feb. 9, 132 British military personnel in Iraq had died or were missing and believed killed since the invasion, said Lt. Col. Simon Etherington, a British military spokesman in Baghdad.

Blair declined to give any clear date for total withdrawal, saying the remaining troops would stay "into 2008 or as long as we are wanted and have a job to do." He added, "Increasingly, our role will be supporting and training, and our numbers will be able to reduce accordingly." He delivered his speech in the House of Commons.

Conservative leader David Cameron embraced the cuts, saying, "That news will be welcomed in this House, in the country and especially to the families of those serving in Iraq over the coming months."

Liberal Democrat leader Menzies Campbell, whose party opposed the war, said: "The unpalatable truth, Mr. Speaker, is this: that we will leave behind a country on the brink of civil war, where reconstruction has stalled, where corruption is endemic, and a region that is a lot less stable than it was in 2003."

Besides the United States and Britain, only five countries have 500 or more troops in Iraq: South Korea has 2,300, Poland and Georgia each have 900, Romania has 600 and Australia has 550, according to the Associated Press.

West European countries have remained largely opposed to the war, while East European countries, including former Soviet republics, have been more enthusiastic. The parliament in Bulgaria voted Wednesday to extend the mission of its 120 noncombat troops in Iraq until the end of March 2008. It also has 35 support personnel there.

Partlow reported from Baghdad. Special correspondents Saad Sarhan in Najaf and Naseer Mehdawi and Naseer Nouri in Baghdad contributed to this report.