Top diplomats on Thursday laid out a series of steps to tamp down violence and political unrest in Ukraine, even as Western officials publicly doubted Russia’s resolve to use its influence to help defuse the crisis in the former Soviet republic.

The potential diplomatic breakthrough, which the Russian foreign minister referred to as “a compromise, of sorts,” came after nearly seven hours of negotiations with Secretary of State John F. Kerry, the Ukrainian foreign minister and the European Union’s foreign policy chief.

Under the agreement, all parties, including separatists and their Russian backers, would stop violent and provocative acts, and all illegal groups would be disarmed. A joint statement made no mention of the presence of what the United States has said are 40,000 Russian troops massed on Ukraine’s eastern and southern borders. But Kerry said it made clear that Russia is “absolutely prepared to begin to respond with respect to troops,” provided the terms of the agreement are observed.

In Washington, President Obama said Russia’s stated commitments were only the beginning of a process.

“My hope is that we actually do see follow-through over the next several days, but I don’t think, given past performance, that we can count on that,” Obama said during a White House press conference. “We have to be prepared to potentially respond to what continue to be, you know, efforts of interference by the Russians in eastern and southern Ukraine.”

1 of 58 Full Screen Autoplay Close April 18, 2014 April 16, 2014 April 15, 2014 Tuesday April 14, 2014 Monday April 13, 2014 Sunday Skip Ad × Ukrainian forces, pro-Russian militants clash View Photos Ukraine is trying to restore order in its east. Caption Pro-Russian­ militants, boasting that they do not take orders from diplomats in Washington or Moscow, refused to end their armed occupation of a dozen government buildings across eastern Ukraine on Friday, upending hopes for a quick end to the standoff. Buy Photo Wait 1 second to continue.

Obama threatened further economic sanctions and stressed American economic and diplomatic support for the Western-oriented government in Kiev. He ruled out a U.S. military response to help Ukraine fend off Russian incursions.

Obama spoke to British Prime Minister David Cameron later Thursday and the White House said the two leaders “stressed that Russia needs to take immediate, concrete actions to de-escalate the situation in eastern Ukraine, including by using its influence over the irregular forces in eastern Ukraine to get them to lay down their arms and leave the buildings they have seized.”

“We will look for the Russians to quickly follow through on their commitments in Geneva in this regard,” a statement from the White House said.

Expectations for the four-way diplomatic session in Geneva were always low, although it marked some diplomatic progress for the Russian and Ukrainian ministers to negotiate directly for several hours. Moscow insists the Kiev government took power in a coup and is illegitimate.

Obama praised the Kiev government’s response to the political unrest and violence in Russian-speaking areas of the country, but sounded unconvinced that Russia intends to do anything to roll back the crisis.

“The Russians signed on to that statement,” Obama said of the agreement in Geneva. The question now becomes: Will in fact they use the influence that they’ve exerted in a disruptive way to restore some order?”

The goal, Obama said, is national elections next month and economic reforms promised by the interim Kiev authorities. The election would bring in a new president to replace Viktor Yanukovych, the pro-Moscow president who fled the country in February. Russian moved to annex Crimea from Ukraine shortly afterward.

The situation remained tense across eastern Ukraine late Thursday. In the port city of Mariupol, where Ukrainian forces engaged pro-Russian separatists on Wednesday night, bloodstains marked the asphalt where three militants were killed and 13 wounded after a siege of a military base there. Remains of molotov cocktails were scattered inside the entrance to the base, where nervous young soldiers tried unsuccessfully to keep onlookers from gazing at the wreckage.

“A mob of 300 militants, wielding guns, molotov cocktails and homemade explosives, attacked the Ukrainian military outpost in the city overnight,” Interior Minister Arsen Avakov said in a statement.

Yet the clash did not appear to signal a newly aggressive stance for Ukrainian forces, who have been treading lightly to avoid giving Russia a pretext to more directly intervene and who suffered chastening losses on Wednesday when militants seized Ukrainian armored personnel carriers near the city of Kramatorsk.

The military set up checkpoints around the city, and officials said newly arrived Ukrainian special forces in Mariupol were still pursuing pro-Russian militants. But there was no immediate sign of an attempt to reclaim the occupied City Hall, though rumors spread of an imminent operation to liberate it. Anti-Kiev militants who seized the building last week were patrolling the grounds and playing Russian folk songs Thursday.

“Let them come, we’ll be waiting,” boasted a 54-year-old factory worker and pro-Russian militant who would only give his first name, Viktor.

Meanwhile, Ukraine’s Border Service said it would begin imposing entry restrictions on Russian men aged 16 to 60. The move prompted outrage in Moscow, and in the eastern city of Donetsk, a group of 60 pro-Russian activists marched on the city’s international airport in protest.

Rejecting intolerance

In addition to disarmament of “illegal groups,” the seven-paragraph agreement called for the return of “all illegally seized buildings . . . to legitimate owners” and said that “all illegally occupied streets, squares and other public places in Ukrainian cities and towns must be vacated.”

As Ukraine’s interim government has previously offered, the agreement also grants amnesty to protesters, “with the exception of those found guilty of capital crimes.”

Referring to a portion of the agreement that “rejected all expressions of extremism, racism and religious intolerance, including anti-Semitism,” Kerry noted that “just in the last couple of days, notices were sent to Jews in one city indicated that they have to identify themselves as Jews, and obviously the accompanying threat implied is, or suffer the consequences.”

“In the year 2014 . . . this is not just intolerable,” he said, “it is grotesque.” Reports of the anti-Semitic notices first surfaced in Israeli publications early Thursday, with reports saying the fliers had been distributed by separatist forces in eastern Ukraine.

Reached Thursday, Judah Kelerman, deputy head of the Jewish Community Association in Donetsk, said that three men wearing balaclava masks distributed a few dozen of the leaflets near the city’s main synagogue on Tuesday. But Kelerman said the incident appeared to be an isolated act and was not being treated as a legitimate threat.

The name of an armed pro-Russian group that took over Donetsk’s regional administration building last week appeared on the pamphlet. But Kelerman said the militant’s leader had disavowed the leaflets Wednesday, and said the group had “no problem with the Jewish community.”

“We are often a target during periods of unrest,” he said. “But we have no idea who these men were.”

Call for accountability

The deal reached in Geneva also included agreement that the Organization for Security Cooperation in Europe, whose monitors are already on the ground in Ukraine, should “play a leading role in assisting Ukrainian authorities and local communities in the immediate implementation of these deescalation measures . . . beginning in the coming days.” It said that the United States, the E.U. and Russia would all provide monitors.

It voiced support for the constitutional reform process currently underway in Ukraine, and insisted that it be “inclusive, transparent and accountable.” The process, it said, “will include the immediate establishment of a broad national dialogue, with outreach to all of Ukraine’s regions and political constituencies, and allow for the consideration of public comments and proposed amendments.”

Kerry called the document “a good day’s work,” but emphasized that “words on paper” were no substitute for action.

“On laying down of weapons,” he said, the responsibility will lie with those who have organized” the separatists, “equipped them with weapons, put the uniforms on them and been engaged in the process of guiding them over the course of this operation…we’ve made it clear that Russia has a huge impact on all of those forces.”

Gearan reported from Washington. Anthony Faiola in Donetsk, Ukraine, contributed to this report.