The chief U.S. envoy to North Korean nuclear talks called Tuesday for rapid progress in shutting down Pyongyang's bomb-making reactor when U.N. nuclear inspectors visit the communist nation next week.

Next week's trip by the International Atomic Energy Agency will be the first concrete step toward dismantling North Korea's nuclear program after a weekend breakthrough in a financial dispute that has delayed implementation of a disarmament accord.

"We want the IAEA to be able to quickly make an agreement and get on with shutting down the reactor," Assistant Secretary of State Christopher Hill told reporters.

• Monitor the nuclear showdown on the Korean Peninsula in FOXNews.com's North Korea Center.

The Vienna-based IAEA said it would send inspectors to the North next week, possibly as early as Monday, to discuss how to monitor and verify the shutdown of the Yongbyon nuclear reactor, as agreed by Pyongyang under the February agreement.

Under that deal reached in Beijing with China, Japan, Russia, South Korea and the United States, North Korea had pledged to shut down the reactor by the middle of April.

There is no new deadline set, however, for Pyongyang to carry through the pledge after the first deadline was missed.

Hill, on a regional tour to Beijing, Seoul and Tokyo, has said he hopes to see a shutdown "within weeks, not months."

Russia's Interfax-China news agency cited an unidentified North Korean official on Monday as saying Pyongyang plans to shut down the reactor in the second half of July.

"Again, we're going to really have to pick up the pace if we're to get back on our timelines," Hill said, stressing the need to make up for time lost due to the banking dispute.

The envoy said he said he has been in contact with the IAEA and it understands the "need to move quickly."

In Washington, Secretary of State Condoleezza Rice welcomed as "indeed a good step" North Korea's invitation of the IAEA team. "We expect North Korea to carry through with its obligations," she said.

The process of persuading North Korea to give up its nuclear program was stalled for months by a dispute over about $25 million in North Korean funds that were frozen in a Macau bank backlisted by the United States.

North Korean state media said Saturday that enough progress had been made on the issue that a "working-level delegation" from the IAEA had been invited to discuss procedures for the verification and monitoring of the reactor's shutdown, as agreed under the February pact. North Korea expelled IAEA inspectors in December 2002.

North Korea had boycotted the six-party nuclear talks for more than a year, saying the financial freeze was a sign of Washington's hostility. It conducted its first-ever atomic bomb test last October.

Hill said Tuesday that the banking issue, which involved the transfer of the money from Macau's Banco Delta Asia to a North Korean account in Russia via the U.S. Federal Reserve and the Russian central bank, is resolved.

"As far as we know, it's been transferred. As of yesterday, we understand that the final glitch ... was resolved. I'm sure the money is in the North Korean bank account today. You should go check," he said as he left for Tokyo.

Hill said the transfer involved "the total amount" of disputed North Korean funds, and said it was "something like $23 million."

It was not clear why the amount is different from what has been reported.

Earlier in the day, Hill said that the North Korean account is in a bank in Vladivostok in the Russian Far East and any delay in transferring the money from the central bank would be due to the vast time difference from Moscow.

South Korea plans to start shipping 50,000 tons of heavy fuel oil to North Korea by the time it shuts down its nuclear reactor as part of the disarmament deal. North Korea is to eventually receive further aid equivalent to 950,000 tons of heavy fuel oil in return for irreversibly disabling the reactor and declaring all of its nuclear programs.

Complete coverage is available in FOXNews.com's North Korea Center.