As Chinese Vice President Xi Jinping visits Washington Tuesday, members of Congress and others are ramping up their calls for China to address a range of issues including the valuation of its currency, its human rights record and Iran’s nuclear program.

Chinese Vice President Xi Jinping, right, gives an opening statement near U.S. Vice President Joe Biden during talks at a hotel in Beijing, Aug. 19, 2011. (Ng Han Guan — Associated Press)

But the measure has stalled in the House, where Republican leaders have declined to bring the measure to the floor, arguing that the White House must first make its position known on the bill.

Sen. Sherrod Brown (D-Ohio), who is up for reelection this year and is one of the strongest congressional critics of China’s currency policy, penned a letter to the White House on Monday calling for stronger enforcement of U.S. trade laws with China.

“China is one of the United States’ largest trading partners — and one of the biggest violators of international trade laws,” Brown said in a statement. “From currency manipulation to rare and raw earth hoarding to its outright subsidization of a wide variety of emerging industries, the Chinese government has shown that it will stop at virtually nothing to give its businesses an unfair trade advantage.”

“This week, as Chinese Vice President Jinping comes to Washington, the White House must take seriously its commitment to protecting American manufacturers and American jobs by standing up to China’s unfair and flagrantly illegal trade practices,” he added.

Late last week, Sens. John Cornyn (R-Texas) and Bob Menendez (D-N.J.) spearheaded a letter signed by 11 Republican senators pressing the Obama administration to “use (Xi’s) visit as an opportunity to address numerous areas of concern over China’s policies and practices.”

Among the concerns they list are: “China’s aggressive military modernization and the lack of transparency regarding the strategic purposes behind it; the importance of strong U.S. support for Taiwan’s security interests; China’s continued undermining of U.S. and international sanctions against Iran; the increasing amount of cyber-attacks and cyber-theft emanating from China; China’s failure to protect intellectual property rights; and China’s ongoing human rights abuses.”

House Ways and Means Committee Chairman Dave Camp (R-Mich.), who is among those meeting with Xi at the State Department Tuesday, issued a statement Monday expressing concern about China’s “closed economy to U.S. companies, ranchers and farmers combined with its long list of trade abuses — including stealing the intellectual property of American businesses, subsidizing domestic industries and undervaluing it’s currency.”

“While Xi Jinping brings a change in leadership for China I am hopeful that this transition also bring changes in policy for the U.S.-China economic relationship,” Camp said. “China has been both an opportunity and an obstacle when it comes to our economy and American jobs. While China is a destination for U.S. exports, China still willfully and blatantly disregards its international obligations and impedes fair business practices.”

Also happening at 2:30 p.m. Tuesday: the Congressional-Executive Commission on China is holding a hearing on the state of China’s treatment of human rights lawyers. Among those testifying at the hearing in the Rayburn House Office Building will be Geng He, the wife of imprisoned Chinese human rights lawyer Gao Zhisheng, and Li Jing, the wife of jailed dissident Guo Quan.

A live Webcast of the event will be streamed here.

Meanwhile, a group of prominent leaders in the national security arena — including Lee Hamilton, Howard Baker, Fran Townsend, William Perry and others — issued an open letter Monday calling for China to “join international efforts to help address Iran’s nuclear program.”

“Putting economic pressure on Iran to prevent its nuclear program from developing into a weapons program is the best way to avoid the kinds of conflicts that represent a danger to regional stability,” said former senator Gary Hart, among those signing the letter. “We are calling on Vice President Xi to take a message back to Beijing that leaders from across the American political spectrum support efforts by the United States, China, and the international community to work together to reduce this threat.”

Their full letter is below.

Dear Vice President Xi,

As a group of American national security leaders from both parties, we welcome you to the United States.

There are few relationships in the world more central to peace, prosperity, and security in the twenty-first century than that between the United States and China. We hope that your visit to the United States will be an opportunity to build ever stronger collaboration between our two countries.

We were delighted when Chinese Premier Wen Jiabao stated last month that China “adamantly opposes Iran developing and possessing nuclear weapons.” We share your government’s view that a nuclear-armed Iran would create dangerous and unpredictable security challenges in the Middle East and beyond.

Like you, we believe that the international community has a responsibility to prevent Iran from developing nuclear weapons and that our countries have the potential to work closely together to prevent this from happening.

As calls for military action rise, we also share your country’s view that a negotiated settlement to this impasse is by far the most desirable outcome. This option, however, will be far more likely if the entire international community, including China, comes together.

Recently, the United States, the European Union, and others have agreed to eliminate their imports of Iranian oil as long as Iran continues to move forward in its nuclear weapons program and in its defiance of the United Nations Security Council. We believe that the value of these sanctions is to encourage the kind of diplomatic breakthrough on Iran’s nuclear activities that both of our nations seek.

In the context of your historic trip to the United States, we therefore urge you to make clear that China will significantly reduce its imports of oil from Iran, uphold the applicable resolutions of the United Nations Security Council, and use its economic influence with Tehran, coupled with robust diplomacy, to help resolve this issue peacefully.

Howard Baker

US Senator (R-TN) 1967-85

Ambassador Paula J. Dobriansky

Undersecretary of State 2001-09

Slade Gorton

US Senator (R-WA) 1981-87, 1989-2001

Lee Hamilton

US Congressman (D-IN) 1965-99

Co-Chair PSA Advisory Board

Gary Hart

US Senator (D-CO) 1975-87

Rita Hauser

Chair, International Peace Institute

Nancy Kassebaum Baker

US Senator (R-KS) 1978-97

John Lehman

Secretary of the Navy 1981-87

Richard C. Leone

President, The Century Foundation 1989-2011

William Perry

Secretary of Defense 1994-97

Frances Townsend

Homeland Security Advisor 2004-08

John Whitehead

Deputy Secretary of State 1985-88

Ambassador Frank Wisner

Undersecretary of State 1992-93