The phrase "aggravate relations" is correct and usable in written English.
It can be used when discussing actions or events that worsen or intensify the relationship between parties, such as countries, organizations, or individuals.
Example: "The recent trade policies have only served to aggravate relations between the two nations."
Alternatives: "strain relations" or "deteriorate relations".
The events are likely to aggravate relations between the French troops and the ethnic Albanians here.
Now, though, Mr. Erdogan appears determined to get him back, a matter that threatens to aggravate relations between the two NATO allies.
The episode threatened to aggravate relations between North Korea and China, a critical source of aid for the impoverished North and one of its few remaining allies.
The developments could gravely aggravate relations between the United States and Pakistan, whose rugged mountains are used by Afghan militants as safe havens.
The lousy performance of the Italian economy, reported on Thursday, is likely to aggravate relations between the European Commission and Italy's populist government, which has pursued spending policies widely regarded as irresponsible.
There had been some concern over the weekend that the South Korean Coast Guard's detention of three crewmen from a Chinese ship fishing illegally in South Korean waters 170 miles south of Seoul might aggravate relations with China, North Korea's most important ally, which has sought to defuse the North-South crisis.
Meanwhile, conflict over oil and territory is aggravating relations between the centre and the Kurdistan government.
But an intelligence coup is useless if it aggravates relations between supposedly friendly states, which is what the Vanunu affair shows every sign of doing.
Touching upon a problem that has aggravated relations with Asian neighbors this year, Emperor Akihito stressed the importance of accurately understanding Japan's wartime legacy in a news conference to mark his 72nd birthday.
Hope Reeves (NYT) ITHACA: EX-TAIWAN CHIEF TO VISIT CORNELL -- Lee Teng-hui, whose 1995 visit to the United States aggravated relations between Washington and Beijing when he delivered a speech with political overtones at Cornell University, plans to visit Cornell again.
Iran's detention of the Americans had aggravated relations with the United States, which is at odds with Iran over issues including its nuclear program and its hostility toward Israel.
