Washington (CNN) The United States and the European Union are finalizing further sanctions against Russia that could be imposed if Moscow takes additional military action in Ukraine, senior U.S. administration officials and European diplomats said Thursday.

The sources stressed that no decisions have been made yet to put additional measures in place. This week's renewed fighting triggered a discussion of additional sanctions, they said, but the fighting ended before a decision to act was made.

The sources said the potential new measures to be presented to Western leaders range from adding names and companies to the current sanctions to imposing broader penalties on Russia's financial, energy and defense sectors.

The point at which Russian military moves would prompt new sanctions is a case of "you know it when you see it," a senior administration official said. "It could be any major assault anywhere across the line of contact. We all know what we are talking about, and we want to be prepared and have stuff ready to go in case we need it."

"There is a whole range of different options leaders will have available to respond to any renewed Russian aggression, to which we could respond pretty quickly and vigorously. We are not talking about weeks," the official said.

Discussion of additional sanctions comes as the EU is widely expected to renew trade and personal sanctions on Russia over its actions in Ukraine when they expire toward the end of the month.

Both the U.S. and EU have linked the lifting of sanctions to implementation of a peace accord hammered out in February by Russia with the leaders of Ukraine, France and Germany in the capital of Belarus.

The so-called Minsk Agreement has been repeatedly violated. The U.S. and EU claim that most of those violations were by Russia and the separatists it supports. Some of the fiercest fighting since the agreement came this week, with heavy artillery fire reported near Donetsk.

Photos: Crisis in Ukraine Ukrainian security forces patrol in the village of Bobrovyshche on July 14, 2015. More than 6,400 people have been killed in the conflict in Ukraine since April 2014, the United Nations says. Hide Caption 1 of 49 Photos: Crisis in Ukraine Ukrainian security forces on the lookout in Bobrovyshche on July 14. The country's troops face daily attacks from Russian-backed separatists despite a ceasefire being in place. Hide Caption 2 of 49 Photos: Crisis in Ukraine A man with a machine gun is among the Ukrainian troops standing guard in Krimskoe town of Luhansk, Ukraine, on June 25. Hide Caption 3 of 49 Photos: Crisis in Ukraine Shelling between Ukrainian troops and pro-Russian rebels leaves damage in Donetsk, Ukraine, on Monday, June 1. Hide Caption 4 of 49 Photos: Crisis in Ukraine A Ukrainian serviceman fires a grenade launcher on the front lines near Donetsk on Saturday, May 30. Hide Caption 5 of 49 Photos: Crisis in Ukraine Pro-Russian rebels carry the coffin of prominent separatist commander Alexei Mozgovoi during his funeral in Alchevsk, Ukraine, on Wednesday, May 27. Hide Caption 6 of 49 Photos: Crisis in Ukraine An American soldier, right, trains Ukrainian troops on Tuesday, April 21, near Yavoriv, Ukraine. Operation Fearless Guardian, a six-month training exercise, involves about 300 members of the American 173rd Airborne and about 900 Ukrainian National Guard troops. Hide Caption 7 of 49 Photos: Crisis in Ukraine Residents flee with salvaged belongings during renewed fighting in the Jabunki neighborhood near the airport in Donetsk on Monday, April 13. Hide Caption 8 of 49 Photos: Crisis in Ukraine A mortar round sticks out of the ground near a destroyed tank at a former Ukrainian army checkpoint outside Chornukhyne, Ukraine, on Monday, March 2. Russian-backed separatists had recently overran the area. Hide Caption 9 of 49 Photos: Crisis in Ukraine An instructor of the Ukrainian volunteer Azov Battalion conducts training exercises in Kiev, Ukraine, on Sunday, March 1. Hide Caption 10 of 49 Photos: Crisis in Ukraine A woman makes her way across a bridge destroyed in heavy fighting in Donetsk, Ukraine, on March 1. Hide Caption 11 of 49 Photos: Crisis in Ukraine A volunteer gives humanitarian aid to residents of Popasna, Ukraine, on Saturday, February 28. Hide Caption 12 of 49 Photos: Crisis in Ukraine A Ukrainian serviceman climbs out of a tank at a checkpoint near Horlivka, Ukraine, on Monday, February 23. Hide Caption 13 of 49 Photos: Crisis in Ukraine A member of a Ukrainian military medical unit cries during a ceremony in Artemivsk, Ukraine, on February 23. Four of his comrades were killed near Debaltseve, Ukraine. Hide Caption 14 of 49 Photos: Crisis in Ukraine A man holds a Ukrainian flag as he covers a victim of an explosion in Kharkiv, Ukraine, on Sunday, February 22. The explosion during a peaceful protest left two dead and 15 wounded. Hide Caption 15 of 49 Photos: Crisis in Ukraine Pro-Russian rebels stationed in Horlivka launch missiles on Wednesday, February 18. Hide Caption 16 of 49 Photos: Crisis in Ukraine Pro-Russian separatists take position near Uglegorsk, Ukraine, on February 18. Hide Caption 17 of 49 Photos: Crisis in Ukraine An army ambulance damaged in recent shelling lies by a road near Svitlodarsk, Ukraine, on Sunday, February 15. Hide Caption 18 of 49 Photos: Crisis in Ukraine Ukrainian servicemen play with a soccer ball on a road between Svitlodarsk and Debaltseve on February 15. Hide Caption 19 of 49 Photos: Crisis in Ukraine A woman salvages items February 15 from the rubble of a destroyed clinic where she had worked in Opytne, Ukraine. Hide Caption 20 of 49 Photos: Crisis in Ukraine People carry a refrigerator through a balcony at an apartment building that was damaged in recent shelling in Svitlodarsk on February 15. Hide Caption 21 of 49 Photos: Crisis in Ukraine A recent ceasefire was brokered during marathon talks in Minsk, Belarus. From left, Belarusian President Alexander Lukashenko, Russian President Vladimir Putin, German Chancellor Angela Merkel, French President François Hollande and Ukrainian President Petro Poroshenko gather before negotiations begin on Wednesday, February 11. Hide Caption 22 of 49 Photos: Crisis in Ukraine People stand beside the body of a woman killed during shelling in Kramatorsk, Ukraine, on Tuesday, February 10. Hide Caption 23 of 49 Photos: Crisis in Ukraine A volunteer gets a medical checkup at a military base for pro-Russian rebels February 10 in Donetsk, Ukraine. Hide Caption 24 of 49 Photos: Crisis in Ukraine Ukrainian volunteer fighters and policemen arrest two men in Kiev, Ukraine, on February 9. The men allegedly arrived from Donetsk and were suspected of participating in pro-Russian rebel activities and organizing terrorist attacks in the Ukrainian capital. Hide Caption 25 of 49 Photos: Crisis in Ukraine Residents unload humanitarian aid in Debaltseve on Friday, February 6. Hide Caption 26 of 49 Photos: Crisis in Ukraine A man rides a bicycle in Vuhlehirsk, Ukraine, on February 6. Hide Caption 27 of 49 Photos: Crisis in Ukraine A child waits on a bus to leave Debaltseve on Tuesday, February 3, after increased fighting in the region. Hide Caption 28 of 49 Photos: Crisis in Ukraine A man stands next to his car in Donetsk on Sunday, February 1, after it was destroyed by shelling. Hide Caption 29 of 49 Photos: Crisis in Ukraine The body of a civilian killed during shelling lies on the ground in Donetsk on Friday, January 30. Hide Caption 30 of 49 Photos: Crisis in Ukraine People in Mariupol, Ukraine, pour soil into the grave of a recent shelling victim on Monday, January 26. Hide Caption 31 of 49 Photos: Crisis in Ukraine Ukrainian servicemen prepare ammunition at a position on the front line near Mariupol on January 26. Hide Caption 32 of 49 Photos: Crisis in Ukraine A man injured during shelling in Mariupol sits in an emergency hospital on January 26. Hide Caption 33 of 49 Photos: Crisis in Ukraine A piece of an exploded missile sits lodged in the ground outside an apartment building in the Vostochniy district of Mariupol on Sunday, January 25. Hide Caption 34 of 49 Photos: Crisis in Ukraine A resident walks by a burning building in Mariupol on Saturday, January 24. Hide Caption 35 of 49 Photos: Crisis in Ukraine A pro-Russian rebel takes cover from shelling in the Kievsky district of Donetsk on Thursday, January 22. Hide Caption 36 of 49 Photos: Crisis in Ukraine People in downtown Donetsk react as Ukrainian prisoners of war are handed over by pro-Russian rebels on January 22. Hide Caption 37 of 49 Photos: Crisis in Ukraine A trolleybus is damaged in Donetsk's Lenin District after its station was hit by a shell on January 22. Hide Caption 38 of 49 Photos: Crisis in Ukraine A rebel takes aim while protecting a supply position in the Kievsky district of Donetsk on January 22. Hide Caption 39 of 49 Photos: Crisis in Ukraine Rubble and debris cover the airport in Donetsk on Wednesday, January 21. Hide Caption 40 of 49 Photos: Crisis in Ukraine Hide Caption 41 of 49 Photos: Crisis in Ukraine Vladimir Bovrichev cries next to the body of his 4-year-old son, Artiam, during Artiam's funeral on the outskirts of Donetsk on Tuesday, January 20. The boy was killed during a Ukrainian artillery strike. Hide Caption 42 of 49 Photos: Crisis in Ukraine Women sit in a shelter during a battle in Donetsk on Sunday, January 18. Hide Caption 43 of 49 Photos: Crisis in Ukraine A building hit by Ukrainian artillery is seen in the Voroshilovsky area of Donetsk on January 18. Hide Caption 44 of 49 Photos: Crisis in Ukraine Men from the Azov Volunteer Battalion board a bus in Kiev to join the fight against the rebels on Saturday, January 17. Hide Caption 45 of 49 Photos: Crisis in Ukraine Rebels sit atop a tank at a checkpoint north of Luhansk, Ukraine, on Wednesday, January 14. Hide Caption 46 of 49 Photos: Crisis in Ukraine A Ukrainian soldier looks down from a military truck at the Donetsk airport on Tuesday, January 6. The airport has been the scene of some of the fiercest fighting in eastern Ukraine. Hide Caption 47 of 49 Photos: Crisis in Ukraine Ukrainian President Petro Poroshenko gives a speech as he hands over new military equipment to forces near the city of Ghytomyr, Ukraine, on Monday, January 5. Hide Caption 48 of 49 Photos: Crisis in Ukraine A Ukrainian volunteer fighter fires a machine gun at pro-Russian rebels near the village of Pisky, Ukraine, on Saturday, January 3. Hide Caption 49 of 49

The European parliament passed a resolution calling on EU governments to keep the measures in place after Russian President Vladimir Putin traveled to Italy Wednesday in what many in the West saw as a bid to break European solidarity on the sanctions.

"Europe has acted with more unity than most people expected, including Putin himself," one of the senior administration officials said.

A European diplomat briefing reporters Thursday noted that this week's violence strengthened European resolve to maintain the current measures.

"The concerns that we all began to feel about additional violations and suggestions there were troops and equipment coming across the border from Russia ... all that in fact was quite useful in getting European nations collectively to grasp that now is not the time to start softening the position we are taking on sanctions," the European diplomat said.

President Barack Obama said in Austria on Monday that he'd convinced European leaders to maintain the economic sanctions. The extension of sanctions was one of his chief goals at this week's G7 meeting in the Bavarian Alps. Obama said Europe and the United States stand ready to impose new sanctions if violence increases.

The sources said that while they prefer not to impose the new sanctions, they hope the knowledge that they are being prepared will deter Putin from taking further action.

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"It is both preparation and also a degree of credible messaging," the European diplomat briefing reporters said. "One is to make very clear that if there are further acts of aggression that we can move quickly. The other is to let it be known we are serious about being ready to do that as a deterrent."

The diplomat stressed, "We would rather not to have to do that, but it needs to be clear that if that is the direction Putin's Russia goes in, that we will react."

U.S. officials and European diplomats insist the sanctions are taking a toll on the Russian economy, where the ruble has plummeted in value.

But they admit the sanctions have done little to prevent Putin from continuing the campaign in Ukraine or curb aggression by separatists in Eastern Ukraine.

In total, more than 6,000 people have died in the fighting in Eastern Ukraine since the conflict began last year, according to the United Nations.