SEOUL, Oct. 6 (Yonhap) -- President Park Geun-hye and U.S. President Barack Obama will send both a strong warning message and overtures to North Korea when they hold summit talks next week, a top U.S. official said Tuesday.

They are scheduled to meet each other in Washington on Friday amid Pyongyang's threats to launch a long-range rocket and conduct another nuclear test.

"We are absolutely united in solidarity with regard to the challenge posed by North Korea," Deputy Secretary of State Antony Blinken told reporters here after meetings with Foreign Minister Yun Byung-se and Vice Foreign Minister Cho Tae-yong.

He urged the North to rethink its stated plan to fire a rocket, which Pyongyang claims is aimed at putting a satellite into orbit.

"If they don't, it's very clear that there will be strong actions taken by the international community," he added. "We've had conversations with Russia and with China and all feel strongly that not only should North Korea not take this step, but it must return to meaningful efforts at denuclearization."

Blinken also refuted speculation that the Obama administration is no longer interested in dialogue with North Korea.

"We remain open to such negotiations, provided they proceed on a credible and authentic basis," he said, citing a recent deal with Iran on curbing its uranium enrichment program in exchange for sanctions relief.

"I think there's an important lesson to be learned from that experience and we hope that North Korea will look at that," said Blinken.

On the Trans-Pacific Partnership (TPP) trade agreement concluded Monday, Blinken said, "We would welcome the opportunity to discuss this with South Korea going forward." South Korea is not among 11 Pacific Rim nations which negotiated the landmark deal.

It is expected to set new global standards for trade, intellectual property rights protection and service sector liberalization. The member states currently account for 40 percent of the world's gross domestic product.

The No. 2 U.S. diplomat, who arrived here earlier in the day for a three-day visit, is on a regional tour that also includes stops in Japan and China.

In talks with his South Korean counterpart Cho, he introduced his impression about a tour earlier Tuesday of the Demilitarized Zone dividing the Koreas. He said it was "quite extraordinary."

Blinken also had lunch with South Korean and American soldiers there, whom he described as "very embodiment of our alliance."

It is Blinken's second visit to South Korea as deputy secretary of state following the previous trip in February.