WASHINGTON: One top national security aide who listened to President Donald Trump’s July call with Ukraine’s president called it “improper.” Another said it was “unusual.” The two testified Tuesday at House impeachment hearings as the inquiry reached deeper into the White House. Lt. Col. Alexander Vindman, an Army officer at the National Security Council, and Jennifer Williams, his counterpart at Vice President Mike Pence’s office, said they had concerns as Trump spoke on July 25 with the newly elected Ukraine president about political investigations into Democrat Joe Biden. “What I heard was inappropriate,” Vindman told lawmakers. Said Williams, “I found the July 25th phone call unusual because, in contrast to other presidential calls I had observed, it involved discussion of what appeared to be a domestic political matter.” Vindman, a 20-year military officer arrived at Capitol Hill in military blue with a chest full of service medals, and said he reported his concerns “out of a sense of duty.” He did so, he said, “because they had significant national security implications for our country.” An immigrant, who arrived in the U.S. as a toddler from Ukraine, Vindman told the panel he was grateful his father brought the family to the…