WASHINGTON, May 23 (Xinhua) -- U.S. Secretary of State Mike Pompeo said Wednesday he was "very hopeful" that the summit between U.S. President Donald Trump and the Democratic People's Republic of Korea (DPRK)'s top leader Kim Jong Un would take place as planed next month in Singapore.

While testifying before the House Foreign Affairs Committee on Capitol Hill, Pompeo said in his first congressional appearance since he took this job that whether the meeting, slated on June 12, would take place is "ultimately up to Chairman Kim."

"We have broad outlines of what it is that each nation is prepared to do," he said, noting that he is hopeful that Trump could convince Kim to make a strategic decision to denuclearize.

Noting that "we are driving on," he said that the United States and South Korea are working to keep the Singapore summit on track.

However, Pompeo said that a "bad deal" with the DPRK is "not an option" for the United States.

"If the right deal is not on the table, we will respectfully walk away" from the coming negotiations concerning Pyongyang's nuclear and missile programs," he said, adding that the U.S. "posture will not change until we see credible steps taken toward the complete, verifiable and irreversible denuclearization of the Korean Peninsula."

The U.S. top diplomat also added that Washington is not intended to make concessions to Pyongyang during the Trump-Kim meeting.

Trump on Tuesday said that the planned Singapore summit with Kim "may not work out for June 12," and "if it doesn't happen, maybe it will happen later. Maybe it will happen at a different time. We will see."

As for Iran's nuke program, Pompeo said the Trump administration is ready to work with other nations to solve the problem.

He said he is to meet with allies in June to discuss the next steps to deter Tehran "threat."

"A number of discussions have taken place below the foreign minister level," he noted.

Venezuelan President Nicolas Maduro on Tuesday ordered the expulsion of the U.S. charge d'affaires Todd Robinson and his deputy Brian Naranjo for staging "enough conspiracies" against his government.

Pompeo said the United States will respond reciprocally to the expulsion, hinting to kick out Venezuela's top diplomat in Washington as well.

Speaking of Russia's alleged interference of U.S. elections, Pompeo said that the United States will not tolerate Russia's bid to interfere in 2018 U.S. congressional mid-term elections in November, and will take "appropriate" countermeasures to counter Moscow's attempts.

However, he admitted that Washington has not yet set up "effective deterrence" to stop the Russian alleged meddling.

Trump has refuted so far Russia's interferences in the 2016 U.S. presidential elections, noting U.S. domestic call for further investigation a "witch hunt" staged by the Democrats to cover their lost.

He believed such investigation aims to illegitimate his presidency, according to U.S. media. Russia has repeatedly denied any involvement in the U.S. elections.