By Lesley Clark, McClatchy Washington Bureau

TOKYO — President Barack Obama spent his first full day of a weeklong Asia trip aimed at renewing U.S. ties to the region with the red-carpeted pomp of a state dinner, a visit to a shrine — where he left a prayer card — and the “full trust” of Japan’s prime minister that the U.S. will back it in a tiff over disputed land with China.

Obama isn’t leaving here with a long-sought agreement on opening up Asia to trade with the United States, but he heads Friday to South Korea with a measure of support from Japanese Prime Minister Shinzo Abe, who repeatedly called him “Barack” during a joint news conference. (The president countered with just one mention of “Shinzo,” otherwise sticking with “Prime Minister Abe.”)

“The United States is and always will be a Pacific nation,” said Obama, who was born in Hawaii and spent part of his childhood in Indonesia. “America’s security and prosperity is inseparable from the future of this region, and that’s why I’ve made it a priority to renew American leadership in the Asia Pacific.”

He toasted what he said was a strengthened alliance with Japan at a formal state dinner at the Imperial Palace, complete with a dessert course of ice cream in the iconic image of Mount Fuji.

The president’s efforts to convince U.S. allies in Asia that the United States is sincere in its efforts to focus on the region have been complicated in part by other foreign entanglements, including Ukraine, and Obama pledged Thursday to impose new sanctions against Russia if it fails to live up to an agreement to quell violence in embattled Ukraine.

“Assuming that they don’t follow through, we will follow through” on threats to impose a new round of economic sanctions in “days, not weeks,” the president said.

The administration struck an agreement with Russia last week in Geneva to hold off on new sanctions if the country removed outlaw militias and took other steps to restore calm.

But Obama said there was little evidence Russia was abiding by the “spirit or the letter” of the agreement and that the administration had been “preparing for the prospect that we will have to engage in further sanctions.”

The president acknowledged that further sanctions “may not change Mr. Putin’s calculus,” but he said they’d be harder for Putin to ignore if other countries cooperated with enhanced sanctions.

The remarks came as Obama reiterated that the U.S. considers a string of tiny islands in the East China Sea to be under Japan’s rule and would rebuff Chinese efforts to take control of them.

Asian allies who share the region with an increasingly assertive China were said to have been rattled by U.S. reluctance to intervene deeply in Syria and Ukraine, but Abe gave Obama unqualified support.

“I fully trust President Obama” when it comes to the U.S.-Japanese alliance, Abe said, adding that the president “exerted strong leadership” in pulling together a global response to Russia’s intervention in Ukraine.

Abe called Obama’s visit a testament to the U.S. administration’s efforts to focus on Asia. Some allies in the region have questioned the initiative as the administration has appeared distracted by domestic budget battles and an array of international conflagrations.

“This greatly contributes to regional peace and prosperity, and Japan strongly supports and also certainly welcomes this,” Abe said of the president’s visit. Abe pledged that his administration, which has strained ties with South Korea — the next stop on Obama’s four-nation tour — “intends to contribute to regional peace and prosperity more proactively than ever.”

The two stressed economic cooperation as well, but failed to reach an agreement on the stalled Trans-Pacific Partnership trade pact, saying only that talks between negotiators would continue.

Obama appeared to gently press Abe on one of the key sticking points: access to Japan’s tightly controlled markets for beef, pork, rice, dairy, sugar and wheat products.

“I’ve been very clear and honest that American manufacturers and farmers need to have meaningful access to markets,” the president said, adding that he “can’t accept anything less.”

Noting that Abe has been pushing to revive the long-stagnant Japanese economy, Obama said he’d told the prime minister that the trade deal was a prime opportunity and had urged “bold steps.”

The visit to the region is aimed at expanding cultural ties, as well, and Emperor Akihito and Empress Michiko received Obama at Japan’s Imperial Palace before he met with Abe.

The president wished the royal family well and noted that he had “very fond memories” of his last visit four years ago. Back then, he joked, he didn’t have any gray hair.

“You have a very hard job,” replied the emperor.

While Obama has visited Japan before, it was the first “state” visit by a U.S. president since Bill Clinton in 1996. Before returning to the palace Thursday night for the black tie dinner, Obama toured a Tokyo shrine and science museum, saying he was a bit freaked out by the lifelike robots, who kicked around a soccer ball.

“I have to say the robots were a little scary,” the president said. “They were too lifelike.”

To Abe’s relief, Obama made it clear that the United States backs Japan in a long-simmering dispute over a chain of islands in the East China Sea. The islands, which Japan and China both claim, are under Japanese administration, the president said, and thus would be protected by the U.S. military should China strike.

But Obama also said the U.S. wasn’t taking sides in resolving the islands’ sovereignty, and he warned that he wants to see the dispute settled peacefully. He said he’d emphasized to Abe the importance of “not escalating the situation, keeping the rhetoric low, not taking provocative actions and trying to determine how both Japan and China can work cooperatively together.”

Abe has riled China by visiting a controversial shrine that honors Japan’s war dead, raising fears of Japan’s past militarism. But Abe said Thursday that he’d done so to pay respects to the war dead and to prevent more wars.

“I renewed my resolve to create such a society and such a world, and I have renewed my pledge not to engage in war,” Abe said.

Obama used the opportunity in talking about the islands to deliver a rebuke to China — and Russia, saying that while the U.S. wants a strong relationship with China, it has to play by international rules.

The alternative, he warned, “is a situation in which large countries, like the United States or China or Russia or other countries, feel as if whenever they think it’s expedient they can take actions that disadvantage smaller countries. That’s not the kind of world that is going to be stable and prosperous and secure over the long term.”

The Chinese government had earlier taken offense at Obama’s remarks on the disputed islands, saying the U.S. should honor its commitment “not to choose sides.”

China rattled nerves in the region last November when it expanded its airspace to claim control of the air zone over the contested waters between itself and Japan.

Obama also met Thursday with relatives of Japanese citizens abducted by North Korea in the 1970s and said the U.S. and Japan were united — along with South Korea — in a bid to rid the Korean Peninsula of nuclear weapons.

Abe, who spoke through an interpreter, said he and the president had talked “heart to heart.” Obama, he said, had told him that the sushi they ate Wednesday night at one of the city’s top sushi restaurants was the best sushi of his life.

AFP Photo/Jim Watson