U.S. Secretary of State Condoleezza Rice flew to Beijing for talks Friday with Chinese leaders on how to enforce sanctions against North Korea amid worries the North might conduct another nuclear test.

Hopes were high that Beijing might discourage its isolated ally Pyongyang from conducting a new test after a Chinese envoy visited the North with a personal message from China's president.

In Seoul, Rice said it was up to each country to decide how to comply with the U.N. sanctions approved after the Oct. 9 test. China and South Korea have balked at inspecting cargo on ships sailing to and from the North. Beijing said that could unnecessarily provoke Pyongyang.

"We want to leave open the path of negotiation. We don't want the crisis to escalate," Rice said Thursday.

Click here for FOX News' North Korea center.

The Chinese envoy, Tang Jiaxuan, met North Korean leader Kim Jong-il on Thursday, the Chinese Foreign Ministry said. A ministry spokesman, Liu Jianchao, said the visit was "very significant" but gave no details of the message from Chinese President Hu Jintao.

Kim told Tang the North would return to nuclear talks if Washington lifts financial restrictions that have angered the North, a South Korean newspaper reported Friday, citing a diplomatic source in China.

"If the U.S. makes a concession to some degree, we will also make a concession to some degree, whether it be bilateral talks or six-party talks," the Chosun Ilbo quoted Kim as saying.

The U.S. financial sanctions were imposed last year on North Korean companies accused of counterfeiting American currency and money laundering and on a bank in the Chinese territory of Macau that dealt with them.

Kim also apologized for the nuclear test to the Chinese envoy, the newspaper reported.

Tang's delegation included Beijing's nuclear envoy Wu Dawei and Vice Foreign Minister Dai Bingguo, according to Liu.

Also Friday, The Asian Wall Street Journal cited officials at four Chinese commercial banks as saying they have stopped moving funds in and out of North Korea in response to a ban by Chinese regulators.

A senior U.S. official confirmed that the Chinese were taking "unusual measures" against the North Koreans in their banking system but would not elaborate. The official spoke on condition of anonymity because Rice had not yet discussed the issue with her Chinese counterparts.

The North says it needs nuclear weapons to counter U.S. aggression.

The United States has repeatedly said it does not intend to attack the North.

The two Koreas are technically at war, since the 1950-53 Korean War ended in a cease-fire.

The North's test challenges U.S.-South Korean ties, long strained by differences about how to deal with Pyongyang. The U.S. wants a tougher line, while Seoul is reluctant to inflame tensions.

Rice has reassured Seoul that the U.S. will defend the country if the North attacks. She brought a similar message to Japan, her first stop on a four-day trip devoted mostly to talks on the nuclear crisis.

Rice has also reaffirmed U.S. President George W. Bush's pledge, made after the North's underground test blast, "that the United States has the will and the capability to meet the full range — and I underscore the full range — of its deterrent and security commitments to Japan."

Click here for FOX News' North Korea center.