RIGA, Latvia – Refusing to enter the debate about whether Iraq has sunk into civil war, President Bush on Tuesday blamed the “dangerous and violent” sectarian strife there on provocative attacks by al-Qaida and said he would press Iraqi Prime Minister Nouri al-Maliki this week about how he plans to get it under control.

Bush said at a news conference in Estonia that he plans to ask al-Maliki for his “strategy” for confronting escalating sectarian violence when the two leaders meet in Amman, Jordan, on Wednesday and Thursday.

The president promised to maintain flexibility in Iraq strategy as he and the Iraqi prime minister discuss the hand-over of responsibility for Iraq’s security to the young government there, but he vowed that U.S. military forces will remain as long as necessary.

“We’ll continue to be flexible, and we’ll make the changes necessary to succeed,” Bush said as he arrived for a NATO summit in Latvia. “But there’s one thing I’m not going to do. I’m not going to pull our troops off the battlefield before the mission is complete.”

Al-Maliki will be asking Bush how the U.S. can accelerate the transfer of responsibility for security to Iraqi forces – and will ask the U.S. to start discussing a timetable for withdrawal of U.S. troops – according to sources within the government in Baghdad quoted by the Associated Press.

But Stephen Hadley, Bush’s national security adviser, said in Riga that he had heard no indication that al-Maliki will be seeking a discussion about the withdrawal of U.S. forces.

“This is a relationship of candor from the get-go,” Hadley said of Bush’s ongoing talks with al-Maliki. “There is a lot of (public) discussion about pushing Maliki. Maliki is doing a lot of pushing himself. He has talked very publicly about his desire to enhance the responsibility of Iraqi security forces.”

Bush, sidestepping a question about whether civil war now exists in Iraq, insisted that the violence there is caused by extremists and terrorists intent on undermining the democratically elected government. He traced Thursday’s bombings in a Shiite-controlled section of Baghdad, which killed more than 200 Iraqis, to a Feb. 22 assault on a Shiite shrine in Samarra.

“We’ve been in this phase for a while,” Bush said at a news conference alongside the president of Estonia in Tallinn before traveling to Riga. “The bombings that took place recently (were) part of a pattern that has been going on for about nine months.

“I’m going to bring this subject up, of course, with Prime Minister Maliki,” Bush said. “My questions to him will be: “What do we need to do to succeed? What is your strategy in dealing with the sectarian violence?”‘

Speaking in a ceremonial hall in the National Bank of Estonia, Bush appeared irritated by a question about what distinguishes the violence taking place in Iraq from a civil war.

“What you’re seeing on TV has started last February,” Bush said. “It was an attempt by people to foment sectarian violence, and … no question it’s dangerous there, and violent. And the Maliki government is going to have to deal with that violence, and we want to help them do so.

“No question it’s tough. … No question about it,” Bush said. “There’s a lot of sectarian violence taking place, fomented, in my opinion, because of these attacks by al-Qaida, causing people to seek reprisal.”

At the Riga summit for the 26-nation North Atlantic Treaty Organization, Bush is pressing for stepped-up commitment to the NATO mission in Afghanistan. The deployment of 32,000 troops represents the first time the European alliance has operated militarily outside of Europe. Bush called the Afghanistan mission the most important task that NATO has undertaken in its half-century history.

NATO Secretary-General Jaap de Hoop Scheffer suggested at the summit opening in Riga that the alliance should be able to start considering a withdrawal of forces from Afghanistan by 2008.

“I would hope that by 2008, we’ll have made considerable progress … (with) effective and trusted Afghan security forces gradually taking control,” Scheffer said.

“Afghanistan is mission possible,” he said. “We need to be frank about the risks, but we also need to avoid over-dramatizing. NATO has been in Afghanistan for three years, time enough to know what it takes to succeed.”

Bush and Scheffer also met privately Tuesday.

“It has been a hard decision to commit forces down there (in Afghanistan),” Hadley said. “It was the right decision. The two of them talked about the importance of the mission in Afghanistan succeeding.”

Bush, in a speech at a university in Riga, reiterated his argument that conflicts with terrorists and extremists in Afghanistan and Iraq are part of a broader conflict between radical militants and democracy.

“Afghanistan is NATO’s most important military operation,” said Bush, noting that the alliance is launching a Special Operations initiative and a strategic airlift operation supported by a fleet of C-17 aircraft. The Bush administration also is pressing some nations, such as Germany, to step up their commitment to involvement in Afghanistan.

“We’re in a long struggle against terrorists and extremists who follow a hateful ideology” and seek to create an empire “from Spain to Indonesia,” Bush said. “NATO has recognized this threat.”

Earlier, in Estonia, Bush insisted that radicals who “can’t stand the thought of a democracy” in the Middle East are fomenting violence in Lebanon. “That’s why you see violence in Lebanon. … That government is being undermined, in my opinion, by extremist forces … out of Syria and Iran.”

Asked about the United States taking part in direct talks with Syria and Iran, Bush reiterated his insistence that the U.S. will not talk with Iran until Tehran proves that it is suspending its enrichment of nuclear material. He left unanswered the question of speaking directly with Syria.

“As far as the United States goes, Iran knows how to get to the table with us,” Bush said. “The idea of this regime having a nuclear weapon by which they could blackmail the world is unacceptable to free nations. … If they would like to be at the table discussing this issue with the United States, we have made it abundantly clear how they can do so.”