Blinken travelled to Kerem Shalom, an Israeli entry point into Gaza a few kilometres (miles) from the southern city of Rafah, where he saw dozens of trucks waiting to enter -- as well as several Israeli military tanks parked nearby.
Blinken, who was escorted by Israeli Defence Minister Yoav Gallant, did not immediately speak to reporters.
However, aides said Blinken raised concerns about the rate of aid entering the Palestinian territory during a meeting in Jerusalem with Prime Minister Benjamin Netanyahu.
After the visit, Gallant said in a statement that the pair "discussed the issue of how to expand humanitarian assistance to Gaza, which would also allow for the expansion of the operational effort", referring to Israel's combat operations.
While at the crossing, Blinken walked around 10 trucks in the process of being inspected by Israeli soldiers.
Speaking the day before in Jordan, the top US diplomat said there had been "real and important progress (on aid), but more still needs to be done".
He has previously called for Israel to do more to ensure the quick passage of humanitarian assistance into Gaza, where the United Nations has warned of impending famine.
Measures that Israel can take, Blinken said earlier, included drawing up a list of goods that would not be subject to arbitrary denial and clearing more drivers to enter the Gaza Strip.
Jordanian aid
Israeli officials sought to show progress to Blinken.
Shimon Freedman, a spokesman for COGAT which coordinates Israeli policy in the occupied territories, said 98.5 percent of shipments were getting through without Israeli objections.
He added that there was a target of clearing 500 trucks a day to enter the Gaza Strip, though well below that figure has been crossing into the territory since the start of the war, according to aid organisations.
Before the visit to Kerem Shalom, Blinken travelled to Nir Oz kibbutz, destroyed by Hamas on October 7, and saw the home of the Kedem Siman Tov family of five US citizens who were killed that day.
The unprecedented attack by Hamas on southern Israel resulted in the deaths of around 1,170 people, mostly civilians, according to an AFP tally based on Israeli official figures.
Israel's retaliatory bombardment and ground offensive in Gaza, aimed at destroying Hamas, has killed at least 34,568 people, mostly women and children, according to the health ministry in the Hamas-run territory.
Kerem Shalom has become a symbol of US efforts to press Israel into allowing more humanitarian assistance into Gaza after the October 7 attacks.
After initially blocking all deliveries into Gaza, Israel reopened the crossing in December under US pressure.
Near Amman on Tuesday, Blinken saw off the first truck convoy of aid supplies from Jordan to go through Erez.
Israel in April also agreed to reopen to aid the Ashdod port near Gaza, which Blinken will also visit on Wednesday, as well as a second crossing from Israel to northern Gaza at Erez.
The Israeli moves came after Biden warned that his support was on the line after an Israeli strike killed seven aid workers from the US-based charity World Central Kitchen.
The Israeli government has repeatedly blamed aid groups and the United Nations for not distributing aid more quickly, but they have accused Israel of holding up deliveries with onerous restrictions and inspections.
