Emb-175 first officer reported ATC issued them a descent clearance from FL350 to FL340. At FL345 a T...

Narrative:

ATC instructed us to descend and maintain FL340 for traffic. On our way down from FL350 to FL340 we received a RA command to maintain vertical speed. The captain initially leveled off at FL345 like the RA stated but the red square was showing 400 and climbing toward us. I instructed we received an RA and are deviating from assigned altitude. The captain pitched up and leveled off at FL350. Traffic passed under our right nose at 400 feet below us. ATC then instructed us to maintain FL350. If we would have followed the RA command we probably would of came a lot closer than 400 feet or maybe hit.as long as pilots aviate and read every situation accidents can be avoided. The captain did a great job of reading the situation and getting out of the way of oncoming traffic.

Original NASA ASRS Text

Title: EMB-175 First Officer reported ATC issued THEM a descent clearance from FL350 to FL340. At FL345 a TCAS RA alerted so the Captain leveled off then climbed back to FL350 as the TCAS target passed 400 feet beneath.

Narrative: ATC instructed us to descend and maintain FL340 for traffic. On our way down from FL350 to FL340 we received a RA command to maintain vertical speed. The captain initially leveled off at FL345 like the RA stated but the red square was showing 400 and climbing toward us. I instructed we received an RA and are deviating from assigned altitude. The Captain pitched up and leveled off at FL350. Traffic passed under our right nose at 400 feet below us. ATC then instructed us to maintain FL350. If we would have followed the RA command we probably would of came a lot closer than 400 feet or maybe hit.As long as pilots aviate and read every situation accidents can be avoided. The Captain did a great job of reading the situation and getting out of the way of oncoming traffic.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1376183
Time
Date	201607
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	EMB ERJ 170/175 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	ATC Issue All Types Conflict NMAC Deviation - Procedural Published Material / Policy

Emb-175 first officer reported ATC issued them a descent clearance from FL350 to FL340. At FL345 a TCAS RA alerted so the captain leveled off then climbed back to FL350 as the TCAS target passed 400 feet beneath.