North Korea's surprise long-range rocket launch has forced it back onto the agenda of re-elected US President Barack Obama, who had all but given up at finding a way to influence the pariah state.

Leadership changes in China, South Korea and possibly Japan could bring fresh dynamics to long-stagnant diplomacy on North Korea, but Obama's response to the launch has been in line with his approach throughout his first term.

The White House warned of consequences for the "provocative" launch, with the UN Security Council convening within hours Wednesday, but released only a written release rather than a high-profile statement by Obama or top officials.

The Obama administration has called its policy "strategic patience" -- refusing to take major initiatives as it waits for North Korea to come around. The United States shifted slightly earlier this year when it agreed to provide food aid, but it rescinded the offer after a failed North Korean rocket launch.

This time, North Korea appeared to be successful with a three-stage rocket whose final portion splashed east of the Philippines. The timing, one year after veteran leader Kim Jong-Il's death, took most observers by surprise.

Victor Cha, who was former president George W. Bush's top adviser on Korea, said there was "an unspoken tendency in the United States to discount these tests as yet another foolish attempt by the technologically backward and bizarre country."

"This is no longer acceptable. The apparent success of this test makes North Korea one of the only non-allied countries outside of China and the Soviet Union to develop long-range missile technology that could potentially reach the United States," said Cha, now at the Center for Strategic and International Studies.

Representative Ed Royce, the incoming chairman of the House Foreign Affairs Committee who in the past has called for efforts to bring down the Pyongyang regime, called for a North Korea policy "with energy, creativity and focus."

"Instead, the Obama administration's approach continues to be unimaginative and moribund. We can either take a different approach, or watch as the North Korean threat to the region and the US grows," the Republican lawmaker said.

Joel Wit, a former State Department official who supports engagement with North Korea, saw a sign for change as South Korea heads into December 19 presidential elections. Both main candidates have pledged to shift from the hard line of incumbent conservative Lee Myung-Bak.

US policymakers are also closely watching China, where Xi Jinping is starting to take the reins of power. China -- seen as the nation with the most leverage over Pyongyang -- quickly condemned the launch.

"Quite honestly, I think the main problem will be the United States because the Obama administration for some reason is comfortable with the approach it's taken towards North Korea," said Wit, a senior research scholar at Columbia University.

Wit said North Korea's growing military capabilities -- and young leader Kim Jong-Un's apparently firm grip on power -- flew in the face of Obama's frequent calls to bolster the US position in Asia.

"I can't understand how an administration can talk about 'rebalancing' or 'pivoting' to Asia when maybe the main security threat in Asia and certainly in Northeast Asia really isn't being addressed," Wit said.

Gordon Flake, executive director of the Mansfield Foundation, said that calls for US dialogue with North Korea were coming only from the outside.

"No one in the administration is saying, 'Oh gee, now that they're successful, we might as well go back to talks with them,'" Flake said.

"I think the standard remains as the president articulated in 2010 when he said we need a sign of seriousness of purpose from North Korea. This is one further indication of a lack of seriousness of purpose on their side," he said.

But Flake, who advised Obama during his first presidential run, said that North Korea could now become a higher priority in Congress.

"By having what appears to be a successful test, there's a risk that this is really going to bump it up in the profile of political issues," he said.

Japan may also see a new leader in Sunday elections, with polls pointing to a return of conservative former prime minister Shinzo Abe, who first rose to political prominence through tough talk on North Korea.