The United States has warned European governments against supporting a Palestinian bid for enhanced status at the United Nations, saying such a move "would be extremely counterproductive" and threatening "significant negative consequences" for the Palestinian Authority, including financial sanctions.

A US memorandum, seen by the Guardian, said Palestinian statehood "can only be achieved via direct negotiations with the Israelis" and urged European governments "to support [American] efforts" to block the bid. The message was communicated by officials to representatives of European governments at the UN general assembly (UNGA) in New York last week.

Palestinian officials accused the US of exerting "tremendous pressure" on European governments to oppose their bid for upgraded "non-member state" status at the UNGA. Announced by president Mahmoud Abbas last week (video), the move is a significant diminution of Palestinian ambitions after its application for full statehood failed last year when it was blocked by the US in the security council.

The Palestinians will wait until after the US presidential election in early November before proceeding with their bid for upgraded status. However, they insist they will press for a vote by the end of the year and are confident of winning a comfortable majority among the UN's 193 countries. The US has no veto at the general assembly.

The memorandum – described by one diplomatic source as "private correspondence" – said the US was continuing to work for a two-state solution to the Israeli-Palestinian conflict, and urged both parties "to avoid provocative one-sided actions that could undermine trust or otherwise distract from the pursuit of peace".

A Palestinian resolution on non-member state status "would have significant negative consequences, for the peace process itself, for the UN system, as well as our ability to maintain our significant financial support for the Palestinian Authority".

It added that a successful resolution could lead to Palestinian participation as a state in international bodies such as the international criminal court. Israel is concerned that Palestinian recourse to the ICC could have repercussions for its policies on settlements, the occupation of the West Bank and the blockade of Gaza.

"We believe your government understands what is at stake here, and – like us – wants to avoid a collision at the coming UNGA session," said the text. "We hope you are willing to support our efforts … We would appreciate knowing where your government stands on this issue. We would also be interested in knowing whether you have been approached on this matter by Palestinian representatives."

Hanan Ashwari, a member of the Palestinian Liberation Organisation executive committee, described the memorandum as "typical American behaviour but also overkill".

"It is ridiculous and unconscionable the way they put themselves at the service of Israel in such a blatant way. This is tremendous American pressure and bias."

She said most European countries had already decided their position on the issue: "I don't think [the US] will make countries change their minds."

Saeb Erekat, the Palestinian chief negotiator, said the memorandum reflected the US position but he hoped that "the Europeans will follow their interests and choose peace over settlements".

One European diplomat said that, until recently, US officials believed a "diplomatic ceasefire" was in force and that the Palestinians would not pursue the statehood issue at the general assembly. But pressure from street protests in the West Bank in recent weeks had stiffened Abbas's resolve, and the current consensus among diplomats was that the Palestinians were determined to press ahead.

There were differing views among European countries on the wisdom of the Palestinians' move, the diplomat added. "The closer we get to the prospect of a vote in the UN general assembly, the more concerned the US administration is likely to be. This letter is an expression of their well-known position against such a vote. But if we are to persuade Abbas not to pull the trigger, a serious alternative needs to be put on the table, and fast."

A second European diplomat said the US had "made it very clear to all of us that they're opposed to any [Palestinian] move at the UN". He also criticised the Palestinians for not engaging in "serious, high-level diplomacy" on the issue.

Some European countries are alarmed at the prospect of the US withdrawing financial support for the Palestinian Authority in the wake of a bid for upgraded status, fearing that the EU would have to fill the funding gap.

Following the Palestinians' acceptance as a state by the United Nations cultural and heritage body, Unesco, the US cut off funding as a punitive measure. The US had contributed 22% of Unesco's annual budget.

Discussions among European governments on whether to support the Palestinians' bid are due to be held this week. However the 27 member states are unlikely to forge a common line.

The US state department declined to comment on the memorandum.