Iranian politicians responded unenthusiastically to a letter sent by members of Congress urging US President Barack Obama to focus on diplomacy with Tehran, saying the missive proved Washington was too confused to hold talks.

Parliamentarian and Foreign Policy Committee chairman Alaeddin Boroujerdi expressed surprise at the letter, which had the support of 131 US lawmakers. Boroujerdi said that it would be studied by the Iranian government, but that the “US congressmen’s change of approach… to ask for negotiations with Iran in a short period of time [after calling for more sanctions against Tehran] indicates the US officials’ instability in decision-making,” according to a Sunday report by Iran’s semi-official Fars news agency.

“Unless we see a change in the positions of the Americans, which can be relied upon, talking about serious negotiations with the US is out of the question,” he added, according to a report carried by Iran’s Press TV.

The letter was deemed “positive” but was described on Sunday as a “small step” by MP Kazzeem Jalali, who sits on the National Security and Foreign Policy Commissions.

“It seems that if the Westerners continue the same trend, some signs of realism will be witnessed in them,” he told Fars News, adding that Western countries must understand that Iran “is the side which distrusts” the West.

The letter, spearheaded by Reps. Charlie Dent (R-PA) and David Price (D-NC), garnered 131 signatures earlier this month, more than a quarter of the House of Representatives. The bulk of the signatories are Democrats, but 15 Republicans signed on as well.

The congressional letter was released just days after Prime Minister Benjamin Netanyahu dismissed Iranian President-elect Hasan Rouhani’s plea for engagement with the United States and called for ratcheting up military pressure. While the letter did not mention Netanyahu, it sharply diverged from the Israeli leader’s calls to increase pressure on Iran and his dismissal of the Iranian president-elect as untrustworthy.

“It would be a mistake not to test whether Dr. Rouhani’s election represents a real opportunity for progress toward a verifiable, enforceable agreement on Iran’s nuclear program that ensures the country does not acquire a nuclear weapon,” said the letter.

“We must also be careful not to preempt this potential opportunity by engaging in actions that delegitimize the newly elected president and weaken his standing relative to hardliners within the regime who oppose his professed ‘policy of reconciliation and peace,’” it said.

In the wake of Rouhani’s June election victory, Obama told the PBS television network that the election appeared to create an opening for more “serious, substantive” engagement with Iran. Congress has frequently been a bastion of resistance to such engagement, but the letter, the number of signatures it has attracted and the seniority of some of the signatories suggest that such resistance is not foolproof.

“I think the way to classify the letter is that there is a diversity of opinion on the path forward in the House,” explained Andrew High, a spokesman for Price.

The letter came after Netanyahu said on “Face the Nation” that the Obama administration should back up its policy of opposing a nuclear Iran with “increasingly forceful sanctions and military action.”

The Dent-Price letter also expressed wariness of Rouhani’s offer, even as it presses the case for engagement.

“We are mindful of the limitations of the Iranian presidency within the country’s political system, of the fact that previous Iranian presidents elected on platforms of moderation have failed to deliver on promised reforms, and of the mixed signals that Dr. Rouhani himself has sent regarding Iran’s nuclear ambitions,” it said.

Several of the signatories on the Dent-Price letter are members of the House Foreign Affairs Committee, which collectively signed a letter to Obama on July 1 saying the election had “done nothing to suggest a reversal of Iran’s pursuit of a nuclear weapons capacity.” The committee dismissed any contention that Rouhani was a “moderate” and called on Obama to expand and intensify sanctions.

A lobbyist who campaigned for the Dent-Price letter said it was his impression that lawmakers signed on in part because they wanted to investigate all options in the wake of US involvement in two controversial Middle East wars over the last decade or so.

A number of the signatories have senior positions in the House. Dent and Price are senior members of the Appropriations Committee, and Rep. James Clyburn (D-S.C.) is the third-ranked Democrat.

The letter also has the backing of J Street, Americans for Peace Now and the National Iranian American Council. The American Israel Public Affairs Committee did not adopt a position on the letter, an official said.