The mobile billboard will keep goading Bush to ''be honest about all allegations of U.S. acts of

torture here and abroad'' in the administration's self-styled 'war on terror' until Jan. 31, when he is scheduled to deliver his annual State of the Union speech to Congress, said Amnesty International USA spokeswoman Sharon Singh.

The human rights watchdog group deployed the mobile billboard as part of a two-week campaign including an online petition. Launched a week ago, that effort so far has drawn ''at least 25,000 signatures,'' Singh said.

''Americans believe in justice and due process, and that everyone is entitled to due process. We have certain values,'' she told OneWorld. ''Ultimately, we the U.S. are seen as an upholder of human rights and we need to continue to do that.''

Amnesty is among a number of organizations and lawmakers calling for an independent commission to investigate alleged mistreatment of terrorism suspects on U.S. soil, at the Abu Ghraib prison in Iraq and the Guantanamo military base in Cuba, and at secret interrogation centers in Afghanistan and other countries.

Also Wednesday, Amnesty sent Bush a letter imploring him to make clear during his State of the Union speech that ''anyone responsible, even at the highest levels, for policies that have led to torture and ill-treatment will be held accountable and to ensure such abuses do not occur in the future.''

In the letter, William Schulz, Amnesty International USA's executive director, said his group welcomed passage late last year of the Anti-Torture Amendment, a piece of legislation he described as ''reaffirming the U.S. prohibition against cruel, inhuman, and degrading treatment.''

Bush signed the legislation, Schulz added, but the president also issued a ''signing statement,'' or legal interpretation of the amendment, stating that it would not bind him in all circumstances.

Further diluting the law was another amendment to the final defense spending bill that for the first time ''allows information gained through torture to be used in military proceedings and restrains the ability of detainees to challenge their detention in federal courts,'' Schulz added.

''Your administration appears to be sending a mixed message about its commitment to stop and condemn torture. It also appears to be creating legal loopholes so as to be able to continue abusive tactics,'' he wrote to Bush.

The Bush administration has defended its practices as legal and necessary to gather intelligence that could help in its fight against terrorists. In addition to raising human rights-based objections to torture, critics have countered that information thus extracted is unreliable and that by torturing foreigners, the U.S. government has increased the risk that its own troops and citizens will be tortured. Additionally, they have said that the use of secret prisons and interrogation centers--so-called black sites allegedly set up by the Central Intelligence Agency (CIA)--is prohibited under U.S. and international law.

While much condemnation has been heaped on the U.S. administration, international attention also has begun to focus on the role that European countries have played in ''extreme rendition''--the clandestine transportation of suspects to black sites or for handing over to national intelligence services in countries where prisoners are tortured.

On Tuesday, Swiss Senator Dick Marty said the U.S. government had moved more than 100 terror suspects through Europe and that governments there likely had known about it.

''There is a great deal of coherent, convergent evidence pointing to the existence of a system of 'relocation' or 'outsourcing' of torture,'' Marty wrote in an interim report to the 46-nation Council of Europe. He added at a news conference that he believed European governments were aware of what was going on.

However, the report said Marty's investigative team had found no direct evidence so far that the CIA had established black sites in Europe itself after the Sep. 11, 2001 terrorist attacks. Rather, the report appeared to confirm what already had been widely reported: that ''hundreds'' of CIA-chartered flights with suspected terrorists on board have passed through numerous European countries en route to places where prisoners are tortured.

A separate European Parliament inquiry has yet to announce its findings on CIA activities in European airspace and territory.

Human Rights Watch (HRW), in its latest annual global review, also faulted the European Union (EU), saying the bloc was undermining the cause of human rights in favor of securing trade deals or cooperation on anti-terror measures.

HRW said the EU ignored abuses in Russia, China, and Saudi Arabia to secure weapons and other commercial contracts. The group chided Britain, France, and Germany for what it termed ''unseemly competition'' to develop relations with Russia despite abuses in Chechnya.

The report reserved its strongest criticism for the United States, which it said used a deliberate policy of abusing prisoners during interrogation, and for three insurgent groups in Iraq--al Qaeda, Ansar al Sunna, and the Islamic Army--which it said targeted civilians with car bombs and suicide bombers.

White House spokesman Scott McClellan rejected the report, released last week. ''It appears to be based more on a political agenda than facts,'' he said.

The British government also is under pressure to come clean about its knowledge of and possible involvement in what UK media refer to as U.S. ''torture flights.''

Britain's Guardian newspaper and New Statesman magazine reported late last week that a leaked Dec. 7, 2005, briefing note from the Foreign Office to Prime Minister Tony Blair's office showed ''a hidden strategy aimed at suppressing debate about rendition'' even as officials admitted privately that people captured by British forces could have been sent illegally to interrogation centers.

British cabinet ministers ''have persistently taken the line, in answers to MPs' [members of parliament] questions, that they were unaware of CIA rendition flights passing through Britain or of secret interrogation centers,'' the Guardian said.

One particularly prominent and persistent questioner, Charles Kennedy, was forced to resign as leader of the Liberal Democrats earlier this month amid revelations that he was addicted to alcohol.